I have been exploring the world of home servers/self-hosting for a little over a year now, and feel like I have at a decent understanding of a lot of things that go into this. The one thing I am not remotely comfortable with yet is networking. It's like a foreign language to me.
What are some good resources or projects that I could work on to help me develop a better understanding of this? Or, what helped you advance your networking knowledge? I have an UnRaid machine and a Raspberry Pi 4 (8gb) at my disposal (for any project recommendations). Current router is ISP provided, so nothing fancy.
If you want dry and boring, do CompTIA and Cisco certs.
If you want fun, get into info sec and learn that way. Check out OWASP, Hackerone, Hack The Box, et al. These platforms will teach you about networking and security at the same time.
Neither is better. Depends on the person.
I recommend getting a VPS and playing around with all kinds of networking tools.