Welcome back. There have indeed been a LOT of changes since PoP, most of them good in my opinion. Bad news first- there are far fewer people to group with these days until you get into the 65+ range. The good news, however, is that soloing is vastly easier than it used to be with the introduction of mercs.
Race is irrelevant anymore; it's best to pick one that you like. Class is probably a tougher choice, but know that any class can be soloed these days, using mercs.
I guess you just need to narrow it down to caster/hybrid/melee, and then to a specific class. Try several that you haven't before, in fact, because it's really not that difficult to start fresh.
If you have any other questions feel free to ask. If you happen to decide to play on Stromm, I'm happy to take in-game questions and provide some help to get started again.