Okay, I’ve installed the theme for you. It uploaded without any issues.
The reason the process is not the same as in the videos of my documentation is because you have installed a WordPress multisite network. I’m not sure if you did that on purpose, but what that means is in order to install any themes you have to first upload and “network activate” them from your Network admin panel in order for them to be available when editing your your individual websites.
In this case you obviously only have one website in your network currently. You may want to consider if you intended to install WordPress multisite or not and contact your web host for help installing a standard WordPress installation. That’s up to you though. It just sounds like this will only confuse you more moving forward if you don’t actually need WordPress multisite.