You cannot smash things at all. But you can blow up rocks and stuff! if you dont have any bombs you can go to the bomb shop in kokoriko village. The bombs are very very expensive, so you should go in with at least 100 rupees. there are also bombs that can work in the water there, and bombs that crawl. hope I helped:)
There's a Goron in Kokoriko town in front on Malo's shop. He's very old and he would ask you to take hot springs water to his son I think in Castle Town. Kill the enemies to clear a path...make sure to do it fast and then you run like crazy. Mostly because some of the enemies will catch up to you and destroy the barrel.