What's my biggest advice?
1. Train hard and don't skip your long runs. I was diligent about my training and the half marathon is still huge not to mention hard. I can't imagine what it would have felt like if I hadn't trained properly. I would highly recommend that you stick to your plan.
2. Know what you're going to do for hydration/nutrition. You need to be hydrated and you need calories to get through 13.1 miles. This is something you should have tested out several times before race day. Experiment on your long training runs. Don't try new clothes, new foods, new anything on race day. Have it all planned out before hand.
3. Dress appropriately. It was only supposed to be about 60 by the time the race ended, so I wore long sleeves. I am so happy I wore a short sleeve under my long sleeve shirt, so I could tie it around my waste until I found my husband in the crowd and tossed it to him. 13.1miles is a LONG haul to have extra clothing wrapped around your waste and I can never bring myself to toss my clothing on the side of the road. I can promise you're going to get warm so have a plan and dress accordingly. Again something to practice on your long run days. Know what temp you need extra clothing. I know for me I need a long sleeve running jacket 45 degrees and below.
4. Be determined and from the start you must tell yourself under no circumstance will you allow yourself to quit. You have to have the right mindset, this is the time for your inner stubbornness to get through it. Running is as just as much a mental battle as it is a physical one. And you have to be ready for that. My 2nd half marathon is when I hit a wall and it almost took me out but even with 3 ambulances passing me I never waived for a ride.....I wanted my medal!!
You can do it!!!