For such purposes, there are video editors. I understand you are new and not familiar with video editing. Watch a video editor like Bolide Movie Creator. It is very simple and affordable. You can use this guide to familiarize yourself with the program and continue to choose for yourself the necessary functions. I mean, choose what you need to do with your video files. Believe me, not all Internet users are familiar with IT and programming. But many have already mastered video editing. And you can master it quickly enough.
