PowerPoint Narrator as a Video tool
One of the most underrated tools for doing short educational videos is PowerPoint. Within PowerPoint, there are tools available that you can use for recording your own presentation audio and video. Additionally, PowerPoint will allow you to do simple video trimming, as well as give you the ability to export your video so it can be uploaded to YouTube or other services.
Record a slide show with narration and slide timings: https://support.office.com/en-us/article/record-a-slide-show-with-narration-and-slide-timings-0b9502c6-5f6c-40ae-b1e7-e47d8741161c#OfficeVersion=Office_365
Turn your Presentations into a Video: https://support.office.com/en-us/article/turn-your-presentation-into-a-video-c140551f-cb37-4818-b5d4-3e30815c3e83
Using PowerPoint Narrator Video Series
Part 1: Recording and exporting a slide
Part 2: Tips Recording your presentation all at once
Part 3: Simple Video Editing – Trimming Video Start and End using Powerpoint