James Cameron and Warner Bros. are about halfway through shooting Avatar 2-5, but we still know almost next to nothing about them aside from the fact that they'll take place on Pandora and a few casting tidbits. Now the BBC has somehow got their hands on documents that may or may not reveal the names of the sequels are Avatar: The Way of Water, Avatar: The Seed Bearer, Avatar: The Tulkun Rider, and Avatar: The Quest for Eywa.
None of those are confirmed, but they seem in line with what we knew. The films reportedly aren't all going to be connected in direct sequel style so the changing names make sense. Cameron had already let us know that the second film, presumably The Way of Water, was going to focus on Pandora's oceans. Eywa is a goddess of the people of Pandora so that's probably going to be some sort of grand conclusion film, and as for the other ones, your guess is as good as mine.
Actually, your guess is probably better than mine. I honestly haven't thought about Avatar outside of writing news stories on it since I left the theater after the first movie. I have absolutely no excitement for this universe, and didn't think the original film was all that good. In fact, I'm not actually sure who is that excited for this. When the original film released I could see it, but I feel like all the wind went out of the sails years ago. Do you ever see someone dressed up in Avatar cosplay anymore? I feel like Cameron and WB think they have this massive cultural juggernaut when in reality they've got a blip that people would have forgotten about by now if not for the sparse reminders that sequels were coming.
The upcoming Avatarfilms are currently scheduled to release in December 2020, December 2021, December 2024, and December 2025.