I definitely would NOT put them together especially if the female is only a year old. She could become gravid while housed with a male and at one year she'd be way too small to safely lay. Two years would probably be risky too unless she's really big for her age. Keep them housed separately for at least the first 3 years and then if you absolutely have to, keep them in the same tank.
It's also important to quarantine him/her for a while. If (s)he did have some parasites or something, you wouldn't want him/her to spread it to the other snake.
Mating season is typically spring and summer but depending on temps and if you brumate your corns, they could mate at any time. Most people recommend, as a rule of thumb, that the female be at least 3 feet long before breeding her.