New-ish player. Don't know what I'm doing outside of following the personal story and world exploration.

What do I do when I hit 80? How do I get geared up to current best in slot? Is there a best in slot? Does it matter? Do I need to have all the expansions to do endgame stuff? (I own up to PoF). I'm coming from the understanding of mmos that ffxiv has given me but beyond that I'm still a bit fresh. I like raiding in xiv, is it comparable to gw2? I also like playing dress-up, so what should I look that for stylish gear to grind?