Nothing quick about what you are asking. But the mechanics is already done. Search inventory/inventories and you will get at least 15 ways to do it.
Examples on forums uses dictionary/array/xml/etc so take your pick.
As Rabenmutter said, don't expect someone to programm the whole thing for you - lol. The forum is great as the folks here are super helpful and can push you in the right direction, some might even have a little time to help you expand a bit.
But I think there is enough on inventories to keep you busy for some time
Going through your post history - seems like you expecting the forum to build your game for you. You want videos, coins, etc etc etc.
Brutally honest here: You say you got a big game to make, that is fantastic, but a big game is going to take you a year or so to make - so you had better decide to get good at it and start learning how to do C2 yourself.
I suggest you open C2 and click new and go through every single template there is and learn the mechanics. What does a platformer got to do with a shop? you say, well nothing... but the mechanics used in the platformer/rpg/car game is the same as any other game, it's just used slightly differently.