I am starting the Liquid diet on Monday 7/31. I have just turned 21, which means all of my friends are turning 21 too, and next Friday night 8/4 I got invited to go to a campout. Is it safe/ok for me to drink alcohol while on the liquid diet (2 weeks) pre-operation? My surgery date is on 8/14

The real answer is ask your doctor and see what they say. My personal answer is probably no, since you're trying to keep your liver as shrunk as possible for the surgery, and this liquid diet is basically practice for after the surgery anyway, when alcohol is definitely a no no. But, again, that's just me, and you should ask your surgeon this question.