New Player - Need Help Leveling

[Niwashi]

Dungeons are still the fastest leveling. And be sure to have your top job keep up with the story quests so you unlock everything. Main or highest level job: alternate between dungeon runs and questing. Alt classes/jobs: alternate between dungeon runs and FATEs, leves, hunting log, etc. The Challenge Log can point you in the direction of lots of things you can be doing and give you a bit of bonus XP itself on top of that.

And you can run FATEs even if there aren't any groups doing so (though it's true a group would make it faster). Since you've hit 30, have you done the My Feisty Little Chocobo quest that lets you have your chocobo fight along with you? That can help make more FATEs soloable if you're having trouble finding groups for them.

Also, side note...when I played on Leviathan a long long time ago, I swear that once I hit 30, I got to look like the BLM with the look at least. Is that not possible anymore, or am I imagining that that happened?

The level 32 dungeon drops the Battlemage Set, useful for all DoM jobs but stylistically looking like BLM. Maybe that's what you're remembering.