One thing you should do, if it has not already been said in class is download a networking program in which you can design a network, to include IP addressing, routers, and switches. One such program is Packet Tracer.
I have provided you the link to download it. It is a very good program and is used in the field today. I just finished a class using the software and it was great.
Here is the link and good luck in class. BTW, you MUST know subnetting!!! Make it part of your life and practice it everyday, know it…