Hold Ctrl and scroll up with the mouse wheel. Edited to clarify, go to the home screen and select a file at random, do not open it. look at your keyboard and find the Ctrl button on the bottom left. HOLD IT, grab your mouse and look for a little wheel that scrolls. Scroll it up to enlarge, down to shrink text size.
Yeah, Everyone understands what a mouse wheel does but that doesn't work when using a laptop with no mouse. I just enlarged the overall text size on my laptop. You can enlarge forms inside returns if you go to view and scroll down to whatever size you want.