Long story shot, we arrived at the block party/family gathering an hour early so we had some time to kill. Don't you worry! I brought my camera and we had a pre-party. It was delightful.
ps. It wasn't my block. It wasn't my family. And yet, I didn't find it awkward, at all. Sure, I mean, people were staring at me, most likely trying to figure out which house I lived at, but it was okay. For example, by the end, they gave me a flag so I could march in the block party parade! I think I was accepted into their neighborhood.