Its only the begining. He is getting older and more interested in exploring his world. Just enforce the nap time by keeping him in his bed and keeping the room quiet and dark. You can't make a child go to sleep but you can set the conditions for it.
I'm assuming that he his pulling himself up in the crib. If he falls over, he will land on the soft matress. Try not to worry, they are tougher than they look.