I had one tom who was very picky and would only breed his favorite hens at the start of breeding season.
He eventually bred all the hens once his favorites went broody.
The spring following the year they were hatched. In my area that is usually the middle of March. If you live farther south it may be sooner. If you provide supplemental light it may be sooner.
My toms usually begin breeding in February.
In my experience the first egg laid by a hen is...