It is hard to give advice when we don't know where you are, at least state or country.
I have had 2 month olds outdoors but they were hatched early enough to be fully feathered and starting to get their adult feathers before first frost, they have time to get used to it as I give them straw in one side of the coop and deep litter in the other side. They don't get heat or light and have done fine, this year had some hatch out a bit later so it's going to be cutting it close they are almost feathered at 2 weeks, but we've already had our first freeze. I take them out so they get used to the temperatures slowly. but the older pullets would pick on them still so may have to make a temp coop in a pen just for them.
The best advice I can is research the breeds you want dependent on your area as to what you would want to get. Also what you are planning for your flock, egg layers meat or dual purpose. For example here our winters here can be brutal you you don't want the big single combs if your flock is going to be out of the heated coop at all, if you let your flock free range you want a cold hardy breed with a small comb to avoid frost bite. Some breeds are better winter layers too.