Leveling is stupid.

[Sieben79]

With an alternate character I hit level 60+ with MSQ, SQ and the daylie Roulette before I even reach the Castrum Meridianum in the storyline.
And the character is a summoner

This link may help you https://ffxiv.consolegameswiki.com/wiki/Experience

Also, if you level up your grand company rank, you can do squardon dungeons that gives you an instant entry in a dungeon.

[Brynne]

Also, if you level up your grand company rank, you can do squardon dungeons that gives you an instant entry in a dungeon.

Seconding the recommendation for squadrons to help level. Instant queues, and you can learn your role and how to play your job as you level. I used to go through Halatali > Brayflox > Stone Vigil > Darkhold when I was leveling, and now I believe there are more above 50, too. If you get the squadron battle manuals from sending them out, they're great to pop whenever you head into a dungeon as well.