Astonishing! You are flying a piece of paper, surfing it on a wave of air created with cardboard.
Next to the dihedral magnus effect glider, the Big Mouth Tumblewing is the easiest way to start flying a walkalong glider. You only need phone book paper or newspaper. The pattern here. This video starts with a introduction, then instructions for making and flying tumblewings.
"Flying Fish" or spinning blimps are simple and quick to make, and you can fly them as walkalong gliders.
I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.