all hens start laying at different times....even within the same breed. most will start between 21 and 25 weeks. It might be a little later w/ winter coming.
Sex linked hens are well known for their egg production, and so are RIRs and leghorns. EEs are more known for the color of their eggs than the amount they give, and delawares are right in between. Once they all start to lay consistantly, which probably wont be untill next since winter is coming and hens slow down their laying in the darker months, u will probably get about 6-7 eggs a day, though if theyre all good layers u can expect 8 often enough. All chickens are different, so nothing is for sure.