Hen or rooster?

[Rena9]

Hi,
New to having backyard chickens...got these chicks at the end of September and heard a potential "cockadoodledoo" yesterday afternoon as I approached the coop. Is this a rooster or hen?
None have began laying yet either. Thanks!!!

That is a very fine looking young roo.

 

[Quail Newbie 3]

I don't know if you can tell by these photos. Any guesses if the white one is a pullet or cockerel. Both are 5 month old frizzles. The black one is a pullet; she's already laid 3 eggs.