FPS Framework help needed

I am trying to learn on how to make a fps system. I have seen a couple of fps framework tutorials on the devfourm and Youtube. But I cant find one that has a kind of “inventory system” (Basically can hold like a Glock, mp5, keycard, etc.) by not only just weapons but also items like a keycard that would open doors and work. I am not sure where to start and cant find any tutorials on how to do this as well as it is a tool. It would help alot if there are any ideas!

(sorry if this is the wrong support section am not sure which section it is)

So you want to utilize the tool type in this framework?