Hi Tammy, I too am having my 1st knee replacement, mine will be on 11th January.
I am an operating theatre nurse, and spent some time working in orthopaedic theatres, so in that respect I am aware of what will happen during the anaesthetic and the actual surgery time.
I have found useful information on this site regarding recovery and other issues arising from surgery and I'm sure you will too.
With regard to being nervous, I too am a little apprehensive, but I think that is normal for everyone to some degree. Something I tell my patients, if they are showing signs of nerves whilst en route to the operating room is as follows.
When you are being nursed on the ward there are a number of patients being cared for by a relatively small number of nurses and care assistants. When you come to theatres you are the focus of attention for a group of professional people, including nurses, surgeons, anaesthetists, operating department practitioners and care workers. As you can see everyone is concentrating on you and this means you are probably in the safest place in the hospital.
I know I am in the UK, but I'm sure the same holds for you in the US.
Here's wishing you well for your surgery and recovery.