If you’re comfortable in the terminal you’ll be fine just starting out and figuring it as you go. Be ready for a few reinstalls but it becomes part of the fun, albeit sometimes frustrating! Go for a mainstream server os like Ubuntu or Debian (as if you google them with any issue you’re likely to find at answer). Get SSH up and running with keys for security, install tailscale and don’t expose to the internet until you feel more comfortable. Install docker then start on one software you think will be useful, get it up and running then move onto the next. I would recommend homepage as a front end then keep it up to date with new software so you can quickly see what you have and what ports are in use. Vaultwarden is useful for the admin passwords. I use authentik for sso but would try caddy if I was starting now.

For personal stuff, i use an external email, and borgbase for backups (highly recommend them if using Borg or restic).

To be honest, you would get frequent notifications for updates that are probably more often than just to remind you. If you’re like me, you’ll just end up ignoring them anyway! There are a lot of small updates to a lot of software, most often not from a security point of view but just as people develop their projects. I update every week if I can but can be a couple of weeks, in which I start to feel “guilty” so when it builds up I know I have to do it

Sorry this doesn’t answer your question really but I’ve had issues when I used to auto update containers so stopped doing that. Some things have breaking changes, others just had issues in that release that caused me issues accessing stuff when not at home. I update every so often when I have ten minutes to do updates, check release notes and deal with any issues if they arise or roll back to that version. I spin up what’s up docker to see what’s changed then when finished, stop the container so it doesn’t keep on polling docker hub using my free allowance.

In short, it could be an option to spin it up, let it run, then stop the container so theres less risk it could be used for an attack.