I had been new to chickens and we got 6 yo 8 week old ones and were fine. You will be fine if they are fully feathered and ready for the coop which is around 6 weeks age.
I have ordered 1 day old chicks from Meyer Hatchery and I am happy with their chickens. Received a lot of compliments at a chicken swap how pretty and great they are looking. Others chickens where about half the size of ours at the same age.
I had no issues with their sexing of the day old...