How to make a video download in a mobile application?

Question

User interface

There is an application in which there is a library of video folders for playing sports (blocks of exercises)
It is necessary to make it so that a person can download these videos, namely the entire folder at once, with the withdrawal of percentages
.
design issues, you need to display some sections of the text on the cloud in the admin panel so that they can be edited
What methods and how can this be done, tell me, I can’t figure it out myself, I’m not very good at this, so I ask you to describe the solution clearly or point by point as -like a teapot)
I don’t understand how to make it so that people can download videos so that when they log in (it’s not about offline mode), they again didn’t download the video for viewing
It's also not clear to me how to make it possible to pause the download and after the button to continue the paused download. How can I do that?
Upload to the cloud. The person on the main page has some text. Let's say Scill, you need to make it possible for a person to change it and the next time you start it, the text that was edited, for example Shef, is taken. A person launches and sees the new Shef instead of the old word Scill.
I don’t understand how to make an admin panel
How to make it so that he can edit this text
What options are there for implementation