I want to put a flat sheet of glass or plastic on my wall for like writing on with those window markers, it would look really cool !
Go to a hardware store like Home Depot or Lowes and ask them how to do it. Some stores will even do it for you. It's safe and professional so don't risk asking us by doing it yourself!
Frost lumber, Dixieline or home depo
There's a Formica like product used on commercial bathroom walls. It come's in 4x8 sheets and would work for you. Any major lumber yard will stock it.
Places that repair glass, or even maybe a Lowes or Home Depot, would have pieces of plexiglass (large plastic).
