How do I make an object available through computer?

Hi, I wanted to make a mod that adds money into the game (similar to the credit card mod but with a larger choice when it comes to the amount) and while I think I know how to make the bills, I'd like to make it available through a computer (and maybe a new object later). The thing is that I know absolutely nothing about mods (I was happy making simple shelves and skirts until now), and I don't know how to do this. I'd really like it if I could make a new "category" for this instead of putting it with the seed packets and other earbuds things, does anyone know how can I do this?

also I noticed that in the game some objects can go into the chest and some can't, how do I make it so that it can go into one?