Is it legal for a 16 year old to date a 12 year old almost 13 year old if they are not having sex?

There are no laws about what age you have to be to date, so it is legal. But there could be problems. There are laws about sexual activity and depending on the state, this is probably not an issue either. In most places you have to be at least 16 to consent, if not 17 or 18.