She's beautiful! 4-H is so much fun!
Yay! Goats are tons of fun and very addicting! Nigerian Dwarfs definitely sound like a good breed for you.
For your first question I don't have Nigerians or live close to New York or Vermont so I can't be much help. Hopefully someone else can speak up, but I do have some advice I can give you. I'm not sure if your county fair has happened yet, but if not you could go and see if anyone has Nigerians there, if they do you can ask the owners where they got theirs. That's how we found our Boer breeder, we went to the county fair and asked the Boer owners where they got their Boers and they all led us to the breeder where we get our Boers now.
You could also ask your vet or other vets in your area, they might know of a few breeders.
I agree with what @oldhenlikesdogs said for your second question.
Not sure on your third question.........we just fenced in an area with some grass that was growing good, lol! I would think probably Home Depot or some place like that but I could be wrong.
Hope I've helped and if you have anymore questions please feel free to ask!