Are there a few lines of code that let you see a number, or variable, printed over the sprite as it moves?

I think you can use GPUTCHR for that. Just make sure the graphics page is over the sprite page.

Also, remember to call GCLS to erase it after each frame. (E.g.: "VSYNC 1:GCLS" or "WAIT 1:GCLS") You can also specify the graphics page to clear with GCLS if you are using a specific page. [Sorry, I forgot this part.]