find the private key dude. I believe that blokchain.info can provide you a private key which sticks to your address and if you can find it, try to import it to the bitcoin cash wallet to receive your bitcoin cash
That sounds pretty simple, so the 12 word phrase is the private key?
No, that's your backup. You need to export your wallet and then decrypt the pk... atleast that's how it works on my wallet. The best option for you personally is to google how to (or if you can) get ahold of your pk from your wallet.