No elements showing up on scene view.

I'm having a problem, I'm making some tests of a game using Unity. It's a 2D project but i wanted to create a canvas to be able to make some counters for score and debugging, but some time after I created a canvas element, the rest of the elements except the canvas and the text weren't showing up on scene view. This is very annoying and it would help a lot if someone could tell me what to do.