I'm having trouble earning money, can someone tell me how to earn money besides doing quests? Thank you!

Explore the Dessert and Jungle whenever you can with your highest level pets. The higher leveled your pets are, the more coins they collect.

Buy pets from the trades under 500 and resell them or send them to the pound. Works best if you're more than a casual player and can constantly monitor trades. This is mainly what I did when I started the game.

Vote for BeastKeeper daily under My Account > Vote. That's 1500 extra coins for a couple of clicks.

Obviously don't buy anything until you've gained a good stock of coins. There are many free pets and blueprints going around for newer players.

Sell any premium store items found in explore. Magic food, which isn't too hard to find can get you 5k each, possibly more. Know the current going price of  the item first, though.

Hope this helps.

Thanks!