Whatever hobby you enjoy, avoid its online community as much as possible. It's a great way to see negativity and arguing, which we all know constant negativity and discourse is fantastic for our collective mental health.
It's also a good way to never actually getting the ball rolling on a new hobby, and instead obsessively research what the "correct" way of doing xyz is and then be too overwhelmed by all the opinions to actually get started yourself.
Not for everything! I find that hobbies which are based around nature tends to have very welcoming and helpful communities online. Gardening, bird watching, hydroponics, that sort of thing.