OK
Have you noticed those mini-enemies walking around the map(for example,in world 1 it's a Goomba)? You have to touch one and battle it. In world 1, you touch the Goomba. Then you go into a battle screen. There are I think 5 Goombas at the bottom. You have to kill them(optional)but the real point is to get the "Toad Coins." There are 8 and you need to cololect them. I hope this answers your question Ananymous.