I have my bitcoin private key, how would I get bitcoin cash and where would I dump it for real bitcoin?
You can use your private keys to get your Bitcoin Cash on any Bitcoin Cash wallet. I personally moved it to Bittrex since they'll support both after the split so I will automatically get my Bitcoin Cash there. Bittrex will allow trading with Bitcoin Cash right away but it won't allow transactions so you could sell it immediately if you want.
I used the android coinomi app and just select the sweep keys option. FYI, the desktop version does not support sweep.