Welcome to the game. Do you have Tri, or Tri-U for the Wii-U?
In any case, Quropeco can be taken down a little bit easier if you have some sonic bombs (Screemer + Gunpowder). When he starts signing, throw a sonic bomb at him, and he will be disoriented for about 5 seconds+. During that time, get a few hits in as best you can.
Quropecos have hard flints, and with wide weapons like hammers, you tend to hit those more often than not. This will decrease your damage conciderably. So, if you don't have clear access to the head, move to his sides and focus on his feet and body. A few fully charged hammer blows to the feet and he will fall down. Then you can smack his head a few times with the golfball swing.
If you are starting out, make sure you learn the full moveset of the hammer. And as always: don't give up! This is the type of game the greatly rewards persistance. If you keep at it, you will be a hammer expert in no time.
As for different weapons to try out on Quropeco... My personal favorite would be the GS. But, stick to one weapon until you are comfortable with it.