I recently traded in my iPhone 11 and the offer dropped significantly. as the battery was below 80%. This is definitely taken into account now, so your XR could sell for much less than the online estimate. You might want to sell it privately. You'll get a better price that way more quickly.
I would probably recommend that you go with programs like QuickBooks or Xero. They both offer robust accounting features and customizable billing options, allowing you to sell individual or bundled lessons at different rates for each client.
Now on the market there are many programs of interest specifically for Mac. You may be interested, but I still found a not bad archiver for mac - Commander One. I hope it helps you!
I don't know if it will work for you, but I can share the article how to mount google drive on mac using Commander One (https://ftp-mac.com/mount-google-drive-mac/)
In general, YouTube on Mac works great! The only thing is constant ads. I know that you can buy a paid version and use it, but I don't want to constantly buy what should be. And so, in general, I like everything. Quality, sound, works great.
I can recommend you to read this article https://mac.eltima.com/plex-alternative/, here is a description of the best alternatives.
Personally, I use Elmedia Player.