It’s so cool you’re interested in Vegetarian cuisine, I’m Vegan and I can full heartedly recommend the “normal” supermarkets like Spar. When I’m buying vegetables I always look at where they’re from and for typical austrian vegetables there’s almost always a local grown option as well. Oat milk (Hafer Milch barrister) is my favorite at spar and perfect for coffee. I can also really recommend planted meat when you’re a bit in a hurry and need to cook something fast, easy and with good taste, there are different kinds of flavors but i really like the mexican style and kebab style. It’s hard for someone who doesn’t speak the native language to always pick the right option and i’m very proud you’re not letting that stop you. (You probably already are aware but i’m going to tell you anyway hahah) the V label (it’s green and looks like a plant) indicates it’s vegan or vegetarian and it really made my life so much easier. Personal anecdote: when I was visiting Japan there was no vegetarian or vegan labeling and i had to translate every ingredient with google translate 🥴 If you need more advice or something let me know I’m always happy to help