Your class is your "school" of fish.
Your good work board could be titled--This work's a keeper!
Your jobs board could be titled--Tackle these jobs
Reading area--Reel in a Good Book
Lunch count--bait? Fish food?
You could use inexpensive items found at yard sales or possible things you have in your own garage to decorate your room. Tackle boxes for supplies. Hang some fishing poles and nets. If you want you could have a small tank of fish. There are many ready-made items for this theme as well. I hope this helps