Idk the age maybe 2 to 3 weeks by feather development got her from a feed store they gave the chick to us for free because it wasn't exposed to be in there the legs are clean and what do you mean the type of comb?
This may help you determine the comb type. It is sometimes hard to tell when they are chicks, before the comb develops fully. It probably has a single comb. It looks like a Production Red or Sex Link chick.