Not dumb questions at all! I purchased my serger almost a year ago and had lots of questions too.
First, one of my own, are you buying it online or through a local dealership? After a lot of research I bought mine from a local dealership even though it was more expensive. The support they give is priceless imo especially because I didn't know much about sergers. I started my research thinking I would buy online. I taught myself how to sew for the most part, so I thought no problem with a serger. I may have been right, but the lessons I got with my serger helped me learn it that much faster. In fact, I just stopped by the store where I bought it and asked another question.
Even if you are going to buy a serger online I would go into a store that sells them and tell them that you are considering buying a serger and ask them to show you how they work. This is what I did and I got a 1/2 lesson right then and ended up going back later that day and buying the serger.
I'm going to be getting a serger soon. I've never used one before. Please tell me the basics on what I need to know to get started.
I suggest getting a book from your local library. I did and enjoyed the opportunity to just flip around and learn what was out there about sergers.
Can I use the same thread as a sewing machine?
Yes, but you'll want cones of thread anyway. The cones you'll use at least in your loopers (the things that wrap the edges of your seam) because they use a lot of thread. You can use these for your needle thread too, or use regular sewing machine thread (which is stronger I understand) because that is cheaper (good cones run about $4-5) and available in more colors.
I have black, white, off-white and red cones that I use for my loopers, then just use regular thread for the needles. That covers me pretty well for whatever I'm making, although I'm thinking about getting gray and navy blue too.
Needles? Or are there special kinds?
Yes, although buy good ones. I used to use the singer needles on my sewing machine but when I bought my serger I started buying schmetz because they're better (I'm told, and seem to be from my experience). Their universal needles work for most everything.
There will be 4 thread options on mine, do I fill them all with the same thread?
That's up to you. You can, but you don't have too, you can have different colors if that suits your project. You can even use crazy decorative threads if you want

What is wooly nylon and why would I want to use it?
It is stretchy thread that will relax to fill the gaps between your stitches for a totally covered seam. I bought some to use for diapers (I was making the poo-pockets ones, which I love) It is really soft so that was nice, but the only thing I didn't like was that velcro will stick to it, so if you're making diapers with velcro add laundry tabs to your design!
I'm going to be using it for diapers, as well as clothing.
You'll love it! So much faster and cleaner than just a sewing machine.
Feel free to PM me if you have anymore questions, now or once you buy your serger. I got some good tips from my lessons and would love to pass on the knowledge!
Good luck & have fun!