Preparation for topper/camper shell install

I purchased 2023 double cab with a six and a half foot bed.

I am planning on installing a camper shell in the next few months.

Besides relocating the bed and rearview mirror cameras is there anything else I need to do before dropping the truck off at the installers? I ask because my 2013 tacoma should have had waterproofing but under the bed rails to help stop leaking. I would like to I have any of these minor fixes completed prior to installation.

Any tips or advice you have is greatly appreciated.

thank you in advance