There is no beta code. I think you will get a email when the beta comes out. You only get the beta if you pre order the game before hand. If there is a beta code, i do not think it will be shareable.
Spend the money so you do not have to worry about this kind of stuff.
I enjoyed the original call of duty online on the ps3 because it was very soothing. Back then , i wasn't playing PC games. Never knew that PC games were better than console gaming. that is why i am excited for this game, i get to play an AWESOME game for the PC at max ultra HD settings.
I don't care about campaign mode but since i bought the game, i shall play it fully. Online multiplayer is gonna be insane especially when they introduce battle royal. it is rumored that battle royale mode would be a 200 man, which is massive in numbers