Leveling up low leveled battle classes a HUGE issue at moment.

[Deathsshadow]

Ways of getting good exp:

Do each guildhest once
Guildhest roulette
Low-level roulette
Challenge Log
Leves
Beast Tribe Quests when you get high enough
Hunting Log
Fates (maybe while waiting for queues)
Always use food +3% exp
FC buff if you can +5-10% exp
Rested bonus

^this. @ OP - No way Your struggling with all these available assets provided above