Vagina Itching and a small red area

Unlikely to be herpes after only 24 hours I would think...
Mostly the herpes virus is only contagious while someone is having an attack - like cold sores and just like those things an attack is more usual when you are at a low ebb. Until then the virus tends to lay dormant in the nerves...

Could be another sort of sti, hopefully mild, but if there is no odour and no discharge your problem is likely to be one of abrasion.
The area around the vaginal opening is very sensitive and some pubic hair is like wire wool and can give a girl something similar to the "beard rash" some girls suffer from after a necking session with a bearded or stubbly fellow if they aren't used to such prickly men...

Similar things can be caused by rough uncared-for hands and nails, a reaction to the soap he uses to wash his hands or perhaps the brand or type of condom.

I suggest you keep the area clean and use a smear of vaseline or even zinc and castor oil cream (nappy rash ointment) and give it a couple of days...
Abstain from intercourse until it has healed.

If it doesn't heal it will be time to visit the doc but I suggest you do that regardless if he didn't wear a condom.