You really don’t need much for a coop at all. When we bought our property it had a tool shed that we converted and it turned out to be way too big for our flock of 12. You could honestly use a large dog house. There are lots of plans online and Reddit has a very good chicken community with answers to any questions you might have.

All that to say: the minimum threshold for starting backyard chicken keeping is very low. I’d recommend jumping in as cheap as possible and upgrading later if you find you enjoy it.

just make sure you have a good lock on your coop and the bottom is closed off (aka not just a frame sitting on the bare ground). raccoons are very good at getting into coops.

You can buy pretty cheap coops at stores such as Tractor Supply that will house half a dozen chickens or so. They're great for people starting out because a number of things, that you might not be aware of, have been integrated and thought through. Also, backyardchickens.com is a popular site for all kinds of advice that we've used to research different chicken matters. In short, it's pretty easy to keep chickens, but you have to do it regularly and with love.

We're on half acre and do a flock of 6 in an enclosure behind the shed. My main piece of advice is get all the infrastructure before the birds. Pay someone to build you an enclosure. Hardware cloth, NOT poultry netting/chicken wire. You need a few nesting boxes and a dry roost for them to sleep. Look up "deep litter method". Woodchips are free, high carbon bedding chicken poop is high nitrogen. The result is incredible compost. Anyway gl.