I am having an very, VERY hard time drawing with the canvas so big (I am used to MS Paint, in which you can just drag the canvas around). Someone please help! ;~;

You can drag while holding down the space bar. I doubt you actually want to change the size of the canvas, (which you can do from the preset menu when creating a project or after the fact by editing the scene settings) you sound like you want to know how to zoom in and out. I recommend reading over the documentation for interface navigation