I'm not the most qualified person to answer these questions, but you need stepping stones and a good looking resume to get to your point Z. If you get to the point where there is nothing left to master there and you have some time in for respectable work history, leave there gracefully and get in somewhere else more challenging. Push yourself. Don't settle for prep cook at point C and move back up again. Keep in mind what your resume reads like to someone 5 years down the road when you make your moves.
The right place will see potential and develop you. There may be better options, and I don't know what you're working with, but you could get into Romano's Macaroni Grill, then learn everything there. I know they do more legit food like making sausage in house and prepping tons of stuff from scratch. Plus working an open line is different. Then do either another Italian place or then switch it up (That's what I would do) to another equal or higher level of dining. You could find part time work doing Italian in a local or family place and pick stuff up there. Work on mastering Italian, or move on and keep that in your tool box when you get into PF Changs or a sushi place. But think about what moves will make sense and are likely feasible to manage your expectations. There are tons of cool jobs I still haven't done yet.
You need to show that you are reliable, but also that you have successfully moved up in a place, and were able to take that somewhere else successfully and hang tight there, and maybe move up there. I've made the mistake of seemingly down-stepping and it is hard to recover from that. You also learn new ways of doing the same thing, different organization and entirely new dishes. I would say get out of Olive Garden eventually though. I think moving from Olive Garden to directly to something actually fancy could be a tough sell. But then again that's just my area. You could get in doing salads and desert and moving up from there. Who knows. Go for it but don't paint yourself into corners with unsure things. Know you won't be stuck at the bottom of one food chain when you came off the top of another. Your last job always counts the most. If you want to really move up in knowledge, which may only help you much later, get other official or unofficial qualifications, like taking little courses or seminars or food events if they're available.
Even if its not directly related. Learn about wine or coffee. Beverage knowledge is becoming much more important these days. Take on part time work to learn new things like baking, gourmet coffee, catering, a whole other line of cooking, even FOH. You're young, so work a lot and find any little way to add learning that may all add up to being able to do something much different and better one day. Go to where foodies and possibly chefs are, and you may talk to the right person. Maybe take another course at the local CC, or get your job to servesafe. I don't know much about corporate restaurants but see if any company would cover tuition for something that may help them too, take some CC courses.
I would say you're better off not chasing the money right away and instead of sticking to Olive Garden too long and getting dragged into management or being older and not much else experience (mistake if you have a different destination ahead, trust me, I've made this mistake), find your next big move, and figure out a few little ones. Besides these choices, the oddest things happen at random. New people you meet quickly become friends and tell you about things they hear from people they know. This is good. It keeps you off CL and gives you at least a toe in a door somewhere.
Get out there to meet and talk with people. I got a cool job once just by mentioning in passing at a bar to some stranger what I was looking for out of sheer interest as we were just talking about the biz and his friend happened to be interested in considering helping me out and ha managed such a place. I worked there for 3 years and learned the second and third coffee waves, seed to cup, coffee tasting and a ton of higher level baking just because some guy that thought I was chill heard me tell him informally that I really wanted to learn it. I never would have applied for that job because I didn't know of the place, maybe even the stars would never have lined up going the main route to that job. I'm not saying branch out like I did, but do anything to build a network. My better career moves have been jobs through people. My worst ones were the jobs that almost thankfully called me 'cuz I was broke or that I tested out on CL.
Never put a place on your resume you didn't do for one year. So try not to take those jobs at all, unless it is part time and you could leave it off but still maybe mention it in a cover letter or interview if relevant. Always highlight those skills though. If you did BBQ for 3 months, mention in your cover letter that it is part of your extensive culinary background. If they care they'll ask and you can discuss it. Also, don't have one new main job every year. Stick it out there awhile longer and maybe do something else around it to keep learning. I'd say since it was where you really cut your teeth, stay there for a total of two years at most if you can. Really master that one job. You'll probably pick up more skill that will travel with you. Get to the point to where you could expertly teach those skills to someone before you leave that foot in the door to cooking. You'll probably get a better reference too. Maybe another raise you can leverage for your next jobs starting pay.
Usually if you've been there a year, they'll want to keep you on because you've been an investment with little pay off so far. They still will want to keep you later on, but they'll also be more understanding if you're clear you appreciate your time with them, but you don't want to run the place and want to learn new things for your career. They'll get it. They'll be willing to help if you gave them a good run. It's the people that want to stay in those jobs for life that probably become a bigger headache to them.
Try to close gaps in your resume. You can fudge a month or two, but it also looks good and reflects your eagerness for learning to the good chefs you want to work for if you have overlapping gigs that kept gaps closed and kept you busy.
Long term: write a master resume and a few basic cover letters as you go. You can tweak these for individual jobs you seek, but don't forget everything you did and learned somewhere. Keep your info straight and correct your whole working life. You usually want to focus on certain things that are more relevant for the specific job being sought, but keep your master resume updated as you go, maybe even have notes you keep to help you bring out details in an interview two years after you did that, and use what matters for each new job. This also keeps it in your head so you are fluent and conversational with your career if you have to talk about it without preparation.
Go to job fairs. Many cities have career events for the food and hospitality industry. Find some place you like and want to learn from and once-in-awhile ask if they have little openings and take those on with your one main job that keeps the bills paid and the resume solid. Find seasonal catering gigs. You can learn great stuff doing catering or even vending gigs for the summer and wedding season. It's a different workflow, and is usually better, but not a real career move unless you own the business. Those guys have lots of cool knowledge they may be more apt to share than in a busy restaurant.
I would say stay out of hotels at this point if you can. They're usually not bad gigs. But you will build real skills in the right restaurants. A hotel is probably more likely to hire a restaurant guy than the other way around. Not that hotel work is less skilled, it is different and not as demanding usually. If you go hotel too long, you may get it good, but may not want to do something else later. Plus, if you want to learn a lot, you probably want to create and explore. Hotels are big structures with little opportunity for this. The decision makers don't even get to do it themselves but sanction other people to work on those components, so you won't get to play as much as if you got into the right spot in a restaurant. Those executive chefs are more like administrators and you can be just some cog. A friend of mine worked in one and you mostly did one thing. They had a saucier. A potato and carrot peeler. A butcher. A guy that did soup. One bread guy. One desert guy. etc. You may get lucky and play rover, but you won't master much like that. If you want to learn a lot, that may not be the best route. Those guys tend to stick around too, so there may less opportunity to advance to do new things unlike the ebbs and flows of the restaurant business. Hard workers can move up fast in a restaurant, but you can stay in the same spot for awhile once you hit lower and upper middle positions.
Do not do institutional cooking. Don't do cafeterias, or "food service" in hospitals or big corporate places. Or non-profits. Like some big chef wants to hire the meals on wheels guy or the guy that made omelets at some Red Cross thing. You won't learn much in theory and those jobs are largely low skill and low paying.
Oh, one reason you may want to stay in Olive Garden for a bit longer. Possible bartending and server experience. Even if you do not want to become a server or a bartender (good gig actually), if you want to be a chef (or owner), those things are good to understand. You may not learn food, but you will learn executing service, which is a packaged deal. Chefs need to communicate or coordinate with FOH people, and often use them in certain ways to do their jobs right. Not all places have a FOH manager or head server etc. That will not hurt at all. It is always good to have some other experience to fall back on as well.
I will say one last thing. Try to get into cooking breakfast at some point in time. Sling eggs in a hot weekend spot and learn those serious moves. Breakfast can be hard, but daytime hours aren't bad. Sometimes breakfast cook jobs are highly sought and coveted just for the daytime schedule and pay. If you can do high volume breakfast, with all of its BS, then you can execute anything once you learn it. Use those free nights to really do something else like some cool part time jobs you may not be able to do otherwise etc, or have a life. Some big restaurants do all three service periods and if you know all three, you're a better hire.
This is just stuff I know relevant to where I live and work. I Hope this helps you though. Good luck.