Paper Selection
The background color really doesn’t matter as long as the pen will show up on the crayon cards. That said I really wouldn’t use a patterned paper for the coloring cards.
The lollipop cards will work with either plain or patterned paper. The base cards on both types of card must be two sided paper. And the paper does have to be fairly heavy, at least 100 lb for both cards.
Cutting
The cricut does all the writing. To make clear lines a medium or thick sharpie works best.
The Cupid bow doesn’t cut well but I got enough to make it look OK. Just be careful taking all the pieces off the mat.