Even with the fediverse, there are a few instances to be cautious of.

One is hachyderm which is run by a British company. It's an instance which engages in petty drama and I would caution someone against using it. It has a veneer of professionalism which might make it appealing to a few.

Another one is universeodon which appears to have been bought out (or something) by a British admin. Petty drama, petty admin drama. Once again, I would caution someone against using it.

.world appears to be a petty censorship instance.

.art is run by a British admin. It is notorious for drama.

There are probably more, but these are ones which immediately come to mind, and they are also ones which someone might overlook as being bad.