I like what both of the others posters responded with. For a newer runner, like yourself, I would suggest something similar to what they are doing, but only around 2 to 3k for your warm-up jog, in consideration of your mileage right now.
Another thing to consider is when your team might arrive, and when you can get on the course. For most of the invites i bring my team to, We need to be on the course 2 to 2.5 hours before or race, as its the only time we can get on the course. My guys will run at least 2, sometimes 3 miles of the course. Then, around 30 to 45 mins before race time, they will jog another 1/2 mile to mile, dynamic warm up, and around 5 strides.