So I've only unlocked the first two worlds/ places and I'm still trying to find Casius, and I'm stuck at the undead ambush. I need a fast and easy way to level up without spending too many coins because I don't have many right now.

Which place are you in?

Enigmatic Grotto?

@wolfywaffle

Yes.

I would suggest missions, it helps level up faster :)

You can also level up quickly in the fest because the enemies are in the same level range as you.

Do NOT put your battle pets on missions. For missions to work, your level-up points and prof points need to be a certain way, and not the way battle pets should be. However, you should have a set of mission pets, since missions are the best way of getting gold. There's a guide stickied in player guides if you don't know how to set up mission pets.

In addition to that, you may be stuck do to how you've set up your team. If you want me to look over your team (and equipment) I can help with that.

Another good way to gt a pet a higher level is to take it to a place that's easier and then they earn experience and get them to a higher level.