Doesn't matter which networking course you take, you need to know the basics of the physical layer. CCNA 1 curriculum focuses in the beginning on the fundamentals of cabling. Making Cables via CAT5E. STP and UDP cables. You wouln't have to make Fiber-optics, but its good to know anyway. Know how to terminate a cable and make it work.
Know the differences between a hub, switch, router, and firewall. They all connect as a network, but they have differences. Router and switch commands dont really come in effect until CCNA 2, so don't worry too much on that.
Networking is an awesome field to get into. I hope you stick with it!