What to do after to you get level 50?

[SirOleas]

Get all battle classes to at least 30 in prep. for 1.21.
Do achievements.
Get 7/7 on all primal weapons.
Get gear from totorak and darkhold in prep. for 1.21.
Work on a gathering/crafting class.
Do class storyline quests for money and achievements.
Do the main story line for money/exp.
Rank up in your grand company for storyline/item perks.
Do all side quests for exp/money/items/achievements.
Grind exp on your current 50 with various gear to convert into materia and stock up/sell it.
Do Chocobo caravans to cap out on GC seals in prep for 1.21/beyond.
Do grand company leves to max out on GC seals in prep for 1.21/beyond.
Make friends.
Help those friends with all of the above.