From this image which hero's should i use. I just started and had gems (I dont know how) but this is what i obtained. Please give some insight on which and why please, thanks.
I would focus on Val and Tree, both have uses far longer into the game. The only other thing you have going is stuns. Champ, TG, Leo and Rev all stun opponents. 5/5 revite if you see one should immediately go on Val. Also per her to 9/10 as quick as possible. Not going to be easy, worth the sacrifice though. You've a long road ahead of you, good luck rolling and enjoy the ride.
I suggest you start over and create new accounts until you roll at least a pumpkin duke. This will allow you to progress through some of the most crucial game modes (dungeons and Here Be Monsters) early on.
Imho, focus on these two (Val and Tree), don't invest too highly on the others.
Being at an early stage, Dracax and Orksbane can be useful but not worth too much investing.
In time I'm pretty sure you'll roll much better heroes.