Not sure where you're located or if urban or rural, but to start off, you just need to decide your actual objectives.
To figure out how many chickens you have space for, this article is very helpful:
How Much Room Do Chickens Need
The highest egg producers, like
leghorns and sex links, are lean, flighty and don't eat as much but do best with free choice feed all day. While you can still eat them, they're kind of puny for meat.
Broilers, like
Cornish Cross, are bred to grow extremely fast, ready for slaughter by around 7-10 weeks. They eat constantly and need to have their feeding time limited. If kept longer than their "process" date, many succumb to heart failure or other health problems.
Raising both types of those birds usually requires separate living quarters, as their needs are so different from each other, and usually the CX get picked on. They can always free range together and some people do have success keeping them together, but it's more work.
I think the most fun are
dual purpose breeds. They're heavy but also fairly decent layers and usually friendly. There are so many varieties and lots of people keep mixed flocks. It's more important to choose heat tolerant breeds if your area gets very hot. Most chickens do just fine in cold weather as long as there's plenty of air flow in the coop. Moisture buildup and poor ventilation are the chickens' worst enemy in winter.
Chicken Coop Ventilation - Go Out There And Cut More Holes In Your Coop!
Here's some great suggestions for
Heat Hardy Chicken Breeds to help you decide.
Keep in mind If you get chicks, they won't be of laying age until 20-ish weeks. But I think raising the babies is the best part!
You Certainly Can Brood Chicks Outdoors
And to make sure you know how to keep those cute fluffy butts safe and secure in their new coop:
Predator Proofing
Please read the above links, they should be super helpful in getting you started

Good luck in your new chicken adventure!!