How to work with the server?

Question

Nginx

Hello. I have a lot of questions about the server, because I just started getting to know it today:
1. I bought a server to upload videos there, and then deliver them to the site from there, before that I used cloud storage, but it’s expensive. I figured out the connection, but I don’t know how to deliver these videos to the site. Question: How to deliver a video to the site via a direct link (or how to make one)?
2. As soon as I bought the server, I climbed it, found the documentation, went to the console, executed a couple of commands: like something like this apt-.... install nginx, and like checking if nginx is working. Then I generated an ssh key, inserted it in the right place, saved it. And then I added this key to the ssh-keys section of the root user. Question: Did I do it right?
3. What console commands do I need?
OS: Ubuntu 16.04 64bit
Installed nginx

Answer 1

1. In the simplest inefficient and unsafe way: add a separate location / video with root to a separate folder where you upload files in any way possible.
There will be a url like test.com/video/123.mp4
2. Quite, just don't forget to disable password authorization if it works fine with a key
3. Hire an admin or read mana