how to use addressables

basically just the Resources folder on crack

Always look up the documentation via the package manager. It can change wildly.

gotchas to watch out for

loading something that is already loaded or in the process of being loaded can throw an error
on complete fires whether you are ready or not
stored by filetype on disk, not script type. ScriptableObjects are your new best friend

just throw it on a plain ol' file server. That's it.
Make sure Build Remote Catalog is set to true in your settings.
If testing with selfhosting, remove the [BuildTarget] from remote load path
Play Mode:Asset Library will almost always work, Test with Play Mode:Use Existing Build
If doing a content update, the content must be in a "Remote Load" group. You can even move stuff from one group to another and it will work.

how to use async/await to make life easy: Just use .Task to allow for awaiting
how to secretly use scene loading: name your scene the same thing as it was in the SceneList. Then you can just replace "SceneManagement.LoadSceneAsync" with "Addressables.LoadSceneAsync"
You can actually host your remote content on Github. Check out the "ServerData" branch on this repo. In your repo settings, go to Pages>Source Branch: set it to whatever branch will host your files