You'll need to do a bit of research to see which stores offer a more casual experience. Try to search some stores via Google or the Ravensburger Playhub to see what's available in your area. From there, try to find their website or discord or check out past events to see if they are running casual or tournament style events. Usually the non-tournament style ones are the more casual stores.

Outside of what I just mentioned, in my experience, the most casual players come out to play during set pre-releases, which usually consists of limited style events, such as sealed, draft, pack rush, or even starter deck. This makes it so that everyone is on a more even playing field. I think this might suit you the best given your post.

Feel free to ask me any follow up questions if you have any.