There’s a self-hosting Community here: !selfhosted
But for a pretty easy and low cost way to get started you can’t go wrong with yunohost - it has lots of music server apps such as funkwhale, amapache etc.
They support communism - so China, Cuba, the old USSR and the modern Russia that is slowly reverting back to communism. So they are supportive primarily of the system no matter how it affects actual chinese, russian or cuban people. The people are of far, far less importance than the system and the more extreme their belief the more they’ll deny the reality of how these regimes treat their people.
That’s not to say it’s all bad - Cuba has some very progressive laws for example but sadly for most of these regimes, dissent amongst the population is not tolerated.
They’re most certainly not Russian or Chinese communists on Lemmy or Reddit as those people wouldn’t be able to access these communities without breaking the law in their countries. That said, my interpretation of who they are as a group is only my opinion based on interacting with some of them.