You can feed them a non-medicated starter a grower or a flock raiser feed. Any of those are fine. Once they get close to laying age you might want to put out a bowl of oyster shell so that as they start laying can eat the extra calcium they need, but only if they need to.
Layer is just chicken feed with extra calcium that chickens need to make egg shells. Once your birds are laying you can decide what you want to do -- feed a layer or feed a grower or flock raiser + oyster shell. Either system is fine. If you have all laying hens of the same breed and age then a layer may be simpler for you.
If you are like me a have a mixed flock of birds that may contain laying and non laying birds or infrequent layers (roosters, young birds, molting birds, breeds that lay less often) then the latter option is good because the birds can regulate their own calcium. They are good at doing that.