Teach me how to use AI video generation platforms Vosu, InVideo, and HeyGen

This project is NOT to make the videos, but to teach me how do I make them myself. I need a short video every now and then, and a video cost one dollar. It is not worth it to post a project for one dollar... (Budget: $10 - $30 CAD, Jobs: AI Video, AI Video Editing, HeyGen, Video Editing, Video Production, Video Services)