Click on the first design, only way to learn how to fold is with a 10 minute YouTube video with plenty of the usual padding to get it to 10 minutes+ and "if you don't have the template" spread throughout.

So basically just buy the $35 worth of books and templates they're selling if you actually want to do this instead of playing and pausing a YT video a hundred times to get through this.

I think I'll fire up Publisher '97 and relive my paper plane memories.