Is the band filled a little when you first have the surgery

That depends on your surgeon. Some put some saline in, others start it empty. Best to ask your surgeon.

mine was empty and had first fill 3 weeks after to let the swelling ease, but each surgeon is different!!

My surgeon told me that it would have next to nothing in it but when I went for my first fill , he said it had 2.4 cc in it from the surgery. (To me nothing meant zero but to him I guess it means 2.4cc?)

I had 2.7cc put in during surgery, but I did not find that out until my first fill appt. I think it really helped so I didn't go through much of a bandster hell and reached my sweet spot very early.