I took the same course about ten years ago. The networking fundamentals I learned in that class are skills I use regularly but the Cisco-specific stuff I forgot almost immediately. I work on Cisco equipment every so often at work, but I manage by reading the documentation and using some Google-fu.

Mostly you need to know the basics. Can you look at an IP and subnet mask and figure out what IPs are in that range? A lot of junior engineers I work with struggle with these concepts and it makes it very difficult to troubleshoot problems.

For self hosting your home network should probably be simpler unless you want a real lab for learning Enterprise gear. I self host everything in Docker and Docker networking adds additional complexity, particularly if you use VLANs too. I wanted to set up wake-on-lan so I could remotely power on a server and it would have been a real struggle without knowing some networking basics to figure out how those packets would travel across those networks.

My advice is to really focus on learning the networking basics, you'll use those everywhere. Don't get too hung up on memorizing iOS commands or things like configuring BGP routing unless you're planning to get certs or become a networking engineer.