You need to click on the tree and then press w. Well, I haven't made anything in a while, and I'm pretty sure we all know the basics of Minecraft. Walk up to trees and click on them to break them, it takes a while though. And while you walk, you'll see more trees. Wow, which means more wood, and your inventory can't store anything yet so it's pointless. But, at least it gives you something to do.
My friend knifeChara is the inspiration for it. Go follow her, even if she doesn't use Scratch anymore. https://scratch.mit.edu/users/knifeChara/