Does this cover need any special prep or sealing before I install it?

The cover ships ready to mount — no prep work required. Once it's installed, the soft material will seal against your bed when folded closed.

What hardware do I need to mount this, and does it come with it?

Mounting hardware is not specified with this listing. Test-fit the cover first to confirm the mount points on your bed, then source fasteners based on your preferred installation method (clamps, brackets, or adhesive-assist options are common for tri-fold covers).

Can I leave this folded up on the cab all day, or will it damage the soft material?

Tri-fold covers are designed for regular folding and stowing — that's their strength. Leaving it compressed against the cab for extended periods is fine. The soft material is engineered to handle daily open-and-close cycles without tearing or degrading.