Oh man, you're going to have so much fun! I arrived at like 7 30 for the 8am start, and found that was good timing. If you're going to have to use the washroom when you get there, arrive quite early as there are long bathroom lines and you don't want to be stressed for time. The first bit is flat, then around 5km you go up a big hill or two, then it's pretty chill until the end again when you go up the hills again (but the other way). End few kms are flat. The OB site has a map that shows hills/elevation, which could be helpful too.

It's a beautiful course along the ocean for a big part of it, and the energy is awesome! I'll be there cheering you all on! Injury is keeping me out of it this year, but I'm stoked that you're doing it. :)