These whiteboards are really awesome especially for the price and size you get. There’s so much possibility with them. Both Home Depot and Lowes have them.
Home Depot: https://www.homedepot.com/p/EUCATILE-1-8-in-x-96-in-x-48-in-White-Hardboard-Thrifty-HDF-Tile-Board-10048616/311314579
Lowes: Doesn’t have online link but it’s available instore for sure.
Amazon: IF you do want a nice glass one that looks great: https://amzn.to/3HLghmA