I usually let mine outside in our big coop at 5-7 weeks but it will definitely depend on the temps outside. I live in Texas, so our chicks tend to be okay outside sooner.
An easy way to tell a pullet from a cockerel is to look at their wing feathers, if they are even lengthed, then it’s a hen. If they are 2 different sizes, they are roos.
*this is not always accurate and may vary on breeds*
Another way you may be able to tell is if they started developing tail...
They did grow up looking the same and the only big difference is that one (Noodles) has some pattern on her chest, and the other (Spring Roll) dosent. They are both layers and I think they may lay very light cream colored eggs. But not quite white, I have a leghorn and the eggs are very close in...