There are many minibosses that you will find across the world. They can walk around the world same as other enemies so that you might encounter them in different circumstances. Elves can be tricky early, but amazons and ghouls should be decent targets depending on your character. You could also try the temple near Kabula or go under the mountain to the east when you get to level 3.
In the recent patch v0.2.5, there is now information about the potential enemy power in their description, so you can decide sooner if engaging in combat with someone you see is a good idea.