I’ve seen videos of little chicks crowing, so I know it can start early, but mine started around 5 months. All my chickens are the same age, and my roo didn’t start mounting until after the hens started laying, maybe around 7-8 months or so. Once the daylight started to get longer in late winter (around 10 mos old) he hit his full stride. His spur growth really increased around then too. You will notice when sexual maturity strikes, many tend to be pretty amourous!!
