I have a Husky tool cart from Home depot that my glowforge sits on. It has 8 drawers. Plus I have a 6’ tall x 48" wide metal shelf unit from costco that I use to store what doesn’t fit in the drawers.
You should browse those results for sure, but the three most popular solutions are something like @johnj’s suggestion, homemade ikea monstrosities, and my personal favorite, the storage solution of kings and/or queens, architectural flat file cabinets.
I have stored a lot on its side but have mechanically supplied the forces of gravity that holds the flat stuff flat even to using a clamp on the wall to hold long boards flat.