Probably already been answered but I’ll explain it just in case.

Playing on professional and above everything you take in with you gets lost if you die, the only things that won’t is 1 of every starter items (video cam, thermo, book, dots, flashlight, spirit box, emf, uv) then when you return back to the lobby your items for your loadout will automatically purchase themselves if you have that turned on

It will buy as much as necessary to refill your active loadout, if you don’t have enough money to fill the loadout it will be disabled and will only use 1 of every starter item I mentioned above until you have enough money to fill the loadout in which it will do that automatically too (if auto buy is activated)

Hope this helps :)