Hi MidnightRose,
I fully agree re Ente Auth. I have it now on all my devices (android, windows 10 and Zorin). I love that it is tied to an email address, not a phone number. Much safer, in my opinion (having previously lost logins when a previous phone died, I was foolishly using google authenticator at the time).
I don't use Joplin, but according to its sync page:
Currently, synchronisation is possible with Joplin Cloud, Nextcloud, S3, WebDAV, Dropbox, OneDrive or the local filesystem.
- NextCloud
I run several websites, and installed Nextcloud on a subdomain of one of my websites. I use the video-chat facility within it as my own private Zoom-equivalent for occasional webchats. I also use it as my own personal filesharing service between my computer, partner's computer, and often being in 2 different physical locations. (It also includes an Office suite which I haven't tried as I use SoftMaker Office.)
I realise this may not be an option for you - but you can rent Nextcloud instances ready set up for you, usually a few $/£/Eu per month.
If you have a NAS, some allow Nextcloud to be set up on it. It also depends if you want to risk opening it up so you can access it from outside your local network.
Nextcloud integrates into Zorin already so it appears in Files as a location. (In Settings -> Online accounts).
There was a thread here recently about using an old mobile phone set up as a local Nextcloud host - that might be fun to try.
- S3
S3 storage is available from AWS (Amazon Web Services) where you would probably fit into their free tier with low usage. Its a bit technical to set up... If you would rather avoid Amazon then Backblaze also offer directly compatible S3 buckets. Their free demo tier is free up to 10MB, enough to check that it works. I use this for off-site storage of a few critical files. Basically it gives you a cloud service totally under your control. It should work well in your situation.
I use Expandrive (a paid for app) which opens Backblaze/Amazon S3 storage within Zorin 'Files'. It also syncs with Google Drive, OneDrive, Dropbox and any FTP or SFTP account, making it easy to drag and drop between these services.
- Dropbox? Another behemoth. I have an account as clients sometimes send me files that way.
Hopefully this gives some avenues to explore.