I also have a Thanksgiving Day 10k, but here in California the air quality might cause the race to be cancelled.

I also just began running again after taking about 6 months off. The first few runs were tough for me, but I was amazed by how quickly my endurance bounced back. Like, after 3 long runs, I was feeling way stronger already.

I suggest you create a training plan for the next week, beginning TODAY. As for diet, I would eat at a slight surplus in order to carb-load.

Sample training plan:

Fri, Nov 16: 5k

Sat, Nov 17: 6k

Sun, Nov 18: 7k

Mon, Nov 19: 8k

Tues, Nov 20: 9k

Weds, Nov 21: Rest the day before the race. Stretch out any sore muscles. Pick out your favorite running clothes to wear.

Thurs, Nov 22 (race day!): 10k