Help set up a small 4 light room

I'm going to be setting up a new room with 4 lights over 2 3×6 beds. It's in a insulated office in a detached garage. The walls are textured and painted already.

I'm buying an 18000 btu minisplit and a 95 pint dehumidifier and will be running a sealed (mostly) environment.

My first question is should I cover the entire room in panda film? Or would I be ok to just caulk all edges and repaint with anti mold exterior paint?

Has anyone here grown in a regular room that didn't have a vapor barrier for a long period of time without running into problems?

I'm becoming a fan of the cheap 4x8 plastic wall panels at HD and lowes. 19.99 for a sheet at lowes..

https://www.lowes.com/pd/Parkland-Plastics-48-in-x-8-ft-Embossed-White-Matte-Plastic-Wall-Panel/3436816


I been using it a lot lately, for many different projects. Way better than paint if you ask me, and they make connector strips for the seams too. I just trowel on vinyl floor adhesive instead of buying FRP glue that is more expensive.

Its rated for food prep area's so doubt it off gasses anything to bad, and resistant to mold and bacteria, and cleans off nicely!