Google search terms: simple origami, dollar bill origami, origami paper airplane,  origami toys

Buying paper: Not widely available in stores, even craft stores as of late. Use normal computer paper in a pinch, or order a wide variety of origami paper packs from Amazon, Etsy, and more.

Tips: the more complex a pattern, the thinner the paper should be for ease of folding! Watch videos of the origami you are trying to fold - sometimes those little pictographs are not good enough! If your paper is too thick for your model, try using a larger sheet of the same paper!