110 lock back after 1.5 years? so lost, please help

hey guys
i am back and have the expansion but i am so confused as to what i do and what all the new features are. does anyone have links to good returning player guides that were decently geared as level 110? are warlocks even still viable in pve and pvp?

Wowhead has a collection of guides to get you back in the loop. https://www.wowhead.com/returning-player-guides

I would peruse the warlock forums to see how they currently play.