Coming back to online poker after 5 years

I used to play online poker on partypoker and pokerstars about 5 years ago and quit due to work commitments. I am thinking of playing again but obviously a lot has changed. I used to play tournaments and sit and gos. What i am asking is advice on which poker sites people use, any HUDs, i have used pokertracker and holdem manager and where to learn or catch up on current meta. Any information would be appreciated, thank you in advance.