We took my two at a similar age and apologies for saying this, it was an absolute nightmare! They were about the same age as yours, but would not stay still while we were trying to get the tent up - we ended up chasing them all over the camp site as they ran into peoples tents, tripped over the guy ropes and generally caused mayhem. They didn't go to sleep until late because of the novelty and noise in the campsite, but then they woke up at 5am and we couldn't keep them quiet. wee only stayed the one night and have never gone back camping again. I can laugh about it now, but at the time it was a bit stressful!
I am sure that you will have a great time even if we didn't.