Multi user backup

I’m a complete noob when it comes to self hosting, and more than willing to learn, but I’m hoping someone can point me in the right direction.

Currently I’m using OneDrive with a family plan, but I want to self host my backups, but have multiple users (whose data is encrypted so only each user can read their own data) and the ability to sync the backup to another server offsite (like a friend’s house).

I’m guessing this is already a thing and there are probably multiple solutions, but I don’t know what they’re called, nor would I know how to compare them.

Ideally I’d like to be able to do other things too, like host a game server etc. so a solution that doesn’t prevent those things would be ideal.

Any help?

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@r_SelfHosted