I recently got into road cycling, my first and only bike purchase has been a Scott endurance bike. Now that I am getting more and more comfortable on a road bike, a couple of guys I group ride with, are encouraging me to try road racing. I have been to a couple "Intro to crit racing clinics" and am thinking of entering my first CAT 5 race. My question is when beginning to road race, is an endurance bike ok to use? or should I consider purchasing a race bike?
Yes, an endurance bike will be fine.
I think most people outside Scott's marketing department would be hard pressed to name the differences.
The main differences are likely to be a longer wheelbase, slower steering, and a more upright riding position. Maybe slightly larger tires, but you can change those to whatever you feel you need.