gameshark 2 confusion

[maymo36]

ok, i just got digimon world 1 for the playstation, and i desperatly needed a gameshark to... help me along the way. so i went to ebay and searched ps2 compatible gameshark and i came up w/ something and bought it. however, it isnt what i thought it would be. it's called gameshark 2, and only has ps2 games on it. idk how it works or how to get the cheats onto my digimon game, so i wanna know how to do it or if it was just a waste of $35. plz help!