Most F-Droid stuff AFAIK should be pretty plug and play. It’ll download an APK which you then just open in order to install the app. You may need a file browser app if your phone OS doesn’t come with one. You may also need to allow installs from third party somewhere in the settings. But android isn’t like iOS and won’t generally restrict your ability to install whatever you want, outside of an options popup to make sure you know what you’re doing.
I don’t use LibreTube personally and can’t speak on that specifically though, if it does something other than just download you an APK file.
It might matter a little more in a 30v1 against angry New York commuters.