HIT MY FIRST LEVEL 30

I literally bought this game a week and a half ago and have been so hooked. My vet is now level 30, what other class should I start next? What’s the most fun class to grind?

I literally bought this game a week and a half ago and have been so hooked. My vet is now level 30, what other class should I start next? What’s the most fun class to grind?