First of all: I am pretty sure you're almost counting hours... and I am wishing you best of luck for your first overnighter!

Now I don't want to be the killjoy here but try not to be too full of expectation as you are starting with some gear not best for every hanger (well, at least not for me ). If the first night doesn't work for you don't give up!

Saying that, let me tell you about my first experiences outside:
My first night in a hammock was with a pad + a sleeping bag. I hated the need to find a perfect position with the pad to find some sleep at all -- took me a long time and whenever I moved at night it started all over again.... well, you have a double, that should be better and help finding a fixed position for the pad.
Another problem I had were cold shoulders -- the hammock hugs you and compresses every insulation between it and you if the insulation doesn't withstand it. Some people add shoulder pads to their sleeping pads -- I am sure there is some thread around here.
My second night out I tried using two summer sleeping bags as a hammock sock (before I even knew about "hammock socks"), that helped a bunch with the laying comfort but brought the need to find a suspension system for the "sock" such that it doesn't hang down loosely -- I needed to have it as close to the hammock as possible to avoid cold air gaps. With a tarp hung low and another regular sleeping bag and an emergency blanket inside it brought me down to -8C on my balcony! I wouldn't have dared to test this in the forest as this temperature has been when I tested this experimental hang for the very first time.

Everything changed with my first UQ-experience! I have almost reached sleeper's heaven now that I have a pretty warm DIY-down-UQ -- feels/sleeps so much better! Next project: new/thicker TQ for really cold nights and I cannot wait for the winter to come . For me it turned out UQ and TQ are the way to go!

I'll need to figure out the meal situation! I have a ton of ramen lying around and some tuna packets. Also, I have some Mountain House breakfast meals and some Japanese Udon noodles. Will have to think of some more easy ones to try out!!
This is an overnighter, right? If youre hiking alot till sleep, bring tuna --lots of energy here. A warm meal in the evening is a very nice thing, maybe noodles? A warm tea before going to bed also helps getting warm. I hiked with french people in France -- they swear that "Verveine" helps going to bed and finding good sleep.
Now, what to eat really depends on you -- I'd say just bring what you would love to eat and bring a little reward for yourself with you!

What do you guys bring as far as spare clothes are concerned? I have convertible hiking pants, wool socks, and a breathable synthetic shirt that I normally hike in. I was thinking about bringing along a spare pare of cotton socks (this ok?) to sleep in, my long underwear (probably wont need), gym shorts, and maybe a t-shirt to sleep in. I don't want to get in the habit of overdoing it on the clothes since I am trying to remain as light as possible.
Presuming the "overnighter" and not much more I'd probably take no spare clothes with me. Fill some cooked water into a bottle to take into the hammock if it gets too cold in the night. Long underwear might help, just in case, but that really depends on the weather there (sorry, I really have no idea how the weather's like in PA). An emergency blanket can prove wonders if weather conditions get worse or your sleeping bag doesn't perform as good as expected...

Now, good luck and have fun hanging out there!