I personally haven’t explored self hosting mail. This thread is a year old but might give you insight from people who have.

I’ve heard about using mailbox.org to do what you’re talking about. It seems the general consensus is getting a clean IP mentioned in the thread linked above is the biggest challenge.

Edit: mailbox isn’t the what I was thinking of. I’ve definitely heard of services that let you self host half of it and just do the send receive part.

Setting up jellyfin, I used docker on debian, and an old Quadro card. What could possibly go wrong?

Turns out that week the Nvidia drivers got a faulty update pushed to debian stable and caused an error with getting the GPU to work in any container. I could either wait a week or pull the simple fix from testing. So impatiently I pulled it from testing.

Learning Linux is a great start.

Learning any coding language will help you understand a bit more about the programs will work, however there isn’t much need to actually learn a specific language unless you plan to add custom programs or scripts.

The general advice for email is don’t. It’s very risky to host and it’s a big target for spam. Plus there’s challenges getting the big companies to trust your domain.

However hosting things behind a VPN (or locally on your home network) can let you learn a lot about networking and firewalls without exposing yourself to much risk.

I have no direct experience with next cloud but I understand it can be hosted on Linux, you can buy a Synology NAS and run it in that, or use something like TrueNAS.

Personally my setup is on one physical server so I use Proxmox which lets me run 2 different Linux servers and trueNAS on one single computer through virtual machines. I like it because it lets me tinker with different stuff like home assistant and it won’t affect say my adblocker/VPN/reverse proxy. I also use Docker to run multiple services on one virtual machine without compatibility issues. If I started again, I’d probably have gotten bigger drives or invested in SSDs. My NAS is hard drives because of cost but it’s definitely hitting a limit when I need to pull a bunch of files. Super happy with wireguard-easy for VPN. I started with a proprietary version of openVPN on Oracle Linux and that was a mistake.