When you go in for surgery the nurses will have you put on a surgical gown where you'll wear the surgical gown in the surgery room and during surgery.
The surgeons will only remove the parts of the gown from your body that need to be removed so that they can do the surgery.
You'll be clothed in the gown during surgery but of course when the surgeon needs access to parts of your body to do the surgery they uncover that part of the body.
Surgery can also seem scary but it really is not much too worry about as doctors have come a long way now as well as surgeons and most surgeries go through without a problem.
You'll be sedated when you go in for surgery so you won't feel anything.