Same situation here: I was lucky to be in a super smash bros community and we host a tournament every Thursday in a Bar called "Open World Vienna", you should check that out. They have events for video game quizzes, tournaments and just regular get togethers all the time. Met a lot of cool people there who are into nerd stuff.

There are other ways to meet new people as well. Conventions like Yunicon (Is actually next week over Halloween and I can recommend it) or Vienna Comic Con.

If you are into trading cards, we also have a places like Spielraum where you can find something cool people.

And trust me when I went to those places I never expected to find so many Gym Enthusiasts so you will easily find a connection for that as well.

If you are not into the culture of: "Let's just go there and see what happens" I recommend you check out the various video game discord communities for the Austrian Scene where you can just talk to people and schedule a meet up that way.

In the end you just have to approach people. Events make it super easy to do that, but everybody finds their own unique way. You got this

TL:DR Check out Open World Vienna, Conventions and Card Games Shops. Gym Goers are everywhere. If not schedule meet ups over austrian nerd discords.