If you attempt something, you try to do it. An attempt is a try. In the image above, Bart is attempting to get the bucket off Homer's head. Do you think his attempt will work? It might!
You could attempt to bake something you've never baked before, or attempt to learn a new game. You could attempt to make friends with someone, or attempt to learn a new language. When you attempt something, you don't know if it'll work, and you might fail, but you give it a shot anyway.
This bunny is attempting to reach an apple, but her attempt fails: