Then maybe it wasn’t for you. Or maybe it’s worth another shot. Try your best to make a good choice of what you want to do and if learning a language is one of these things and you believe Duolingo is a good way to do so, commit yourself and try again. And don’t worry too much whether it’s the right or wrong thing, it’s not a permanent decision (but if you decide on it, don’t abandon it too soon either).
I will add to others’ comments, that although this is the default on the communities list, make sure the “Local” option is selected to see all communities on the specific instance or “All” to see all communities the instance federates with (in other words, all the communities it allows access to)