First extraction ever

I had my first molar extraction today and I was left with a gauze that the dentist told me to bite down on for 30 minutes. I got home and it still had blood on the gauze so I put another gauze for third minutes. I took it off and it still had blood stain. I’m thinking the red I’m seeing is just from biting down on the gauze. Am I supposed to wait till it’s white completely??

Secondly can I eat?

Thirdly I’m a smoker and I’m craving one. I was told to put a gauze before I smoke by the dentist.