Let me fill you in on an ultimate truth.
With use, all knife edges dull. The only way to avoid dulling any particular knife is to never use that knife.
If you want to use a knife and to keep it sharp, you are going to need to sharpen it on a regular basis.
To slow down the dulling of the edge, you are also going to need a cutting surface which does not unnecessarily dull the edge.
Those are basic, unalterable truths.
That being said, you are going to need to buy more than just a knife. You also need a sharpening system and you need a good cutting board. My personal reaction for someone setting out to outfit a personal kitchen is to spend on each category.
You need a chef's knife (a minimum of 20cm in the length of the blade), a very small paring knife (somewhat around 7cm to 9cm in the length of the blade) and a serrated edge blade for bread and other foods with a tough outer skin and a soft interior (with a minimum blade length of 25cm).
I prefer basic working knives. I am not a fan of fancy blades. In particular, I do not like damascus blades. I find them to be blades which require a lot of energy and effort to keep looking good, without any cutting performance advantage to them.
I would recommend a MAC HB-85 chef's knife - 21cm blade length, decent quality steel that can hold an edge (though obviously not forever). The balance point is just forward of the handle scales. This is a tool - it's definitely not fancy. There's no bolster. The price is 75 euros. The nearest European distributor is in Germany. https://www.kuechenmesser.de/HB-85-MAC-Chef-Kochmesser-215-mm-Klingenlaenge
For both the paring knife and the bread knife, I would recommend Victorinox fibrox handle knives. These are decent quality basic knives at modest price.
For a cutting board, I would choose a good quality edge grain wood board (in Europe, beech is often liked). The minimum dimensions for such an edge grain board need to be about 30cm by 45cm by 5cm thick. I will leave searching for that up to you.
For sharpening stones, I would recommend water-based lubricant stones only (usually referred to as "waterstones"). The minimum size should be 5cm by 20cm (though bigger is better). I will leave searching for that up to you.
Since you are in Austria, with a budget of 250 euros, first figure out how much taxes will be. Then figure out how much after taxes you can really spend. Then plan accordingly.
I am in the United States, so I don't have a full knowledge of European Union laws, rules and regulations. Hopefully, benuser will have more details.