Hi @OlanrewajuK415, I'm not an Android user myself but, before anyone else jumps in, I found this article that might help you our with this: https://www.howtogeek.com/201843/how-to-trim-and-cut-videos-on-your-android-device/
Let me know if it works!
In your other thread, you said you were using your iPhone.
I have a question for you: Are you really going to try to create a complete course just with your cell phone?
If you have a good device, you can definitely use your phone's camera to record some lessons. Many people do that, but if you want to create a high-quality course in a reasonable period of time, you will need a computer. Do you have one?
I asked you two questions , so I'm not sure which one you answered.
If you have a computer, then you will most likely produce your videos there, so, why not split your video there instead of on your cell phone?