So I started out doing the different class's guild story lines as suggested thinking that I'd try to treat the experience as though I was a new player. The problem that I soon experienced was that, in having all the classes already leveled, I progressed through the story lines way way faster than I would have if I had started anew and, because I had little incentive to do all the side quests or dungeons, i was still left with little to no real experience with the different classes I was working through.
I accidentally decided to start doing the random low level dungeon roulette while trying to play with my new PS4 UI and...BAM!!! I remembered why I love this game.
After running all of the low level dungeon options with my gladiator, I am convinced that this is the best way to get back into this game...

This post was way longer but for some reason it won't let me post it. Thanks guys for the advice