You will need running shoes, a water bottle, and a reflective vest or other reflective gear.
You should go to a running specific store such as Bryn Mawr to get fitted for shoes.
Dry fit (wicking) apparel is recommended for the warm weather. It is also recommended to wear a watch ( a simple one that tells minutes and seconds is fine).
Spikes are also suggested but not required for races.
Here is a link to the type of vest you will need. It does not need to be this specific vest, but something similar and that is reflective.
http://a.co/hJzaOXO