You might want to try wwoof'ing first (
https://wwoofusa.org/forums/forum/all-wwoof-forum/). Just to get a feel for people looking for a "community" type setting, but with a short term commitment. That way you can get some experience with living with folks "in community". And experience with what people say before you actually meet, and what they are like after they arrive.
As for the question your friends have about "illegal activities" (which I interpret to mean drug use), we used to say "you are adults, be cool, keep it to yourself, ..if you have to do that". We have learned that rarely works out. We now say, "If you must do that, you are welcome to, just not here, find somewhere else where they think it's ok.". We have found it is much better to spend time experiencing the wonders of gardens, and raising animals, and laughing together, and just living in general, ...than being concerned about your next "high".
Living together with people other than long term friends or family can be difficult stuff. Your concerns are not the least "over the top" when compared to reality. If you wish to talk more in depth, PM us.