There are a number of people on this site that are better suited to answering this particular question, but let me put my 2¢ in (0.235 Euro)
Simply put no you do not need to go to culinary school to be a bread baker. School will offer you a well rounded education that will make you better suited to work in a given industry. It is possible to apprentice (or at least work for awhile and absorb what they're doing) at some places. You may well learn all you need to know from that. That being said there are also schools that specialize in bread baking do some research.
As far as your second question; "how much money can be made owning a bread bakery."
That is almost entirely up to you. You can make as little or as much as you like. You can have a small family artisan bakery and make enough to survive, or maybe be popular and make a nice living. You may turn it into a chain and make a freakin fortune! Money is a large function of your desire, dedication and business savvy that can't always be learned. There are many people that went to the prestigious Wharton school of business. Many make a lot of money, many make a fortune, many likely just make it, and then there's the occasional Donald Trump. The point being, there are a lot of ways of being successful in the hospitality industry, and also in the bread making biz, that will be up to you.
Good luck!
Here are a couple of links that might help:
http://www.progressivebaker.com/ http://www.bakingandbakingscience.com/