Greetings and welcome to BYC! So glad you joined us. There's a wealth of info, knowledge and experience shared in the multitude of threads. There's one dedicated o coops containing thousands of pictures. Browse around and see what interesting stuff you can find. By all means post away when the desire strikes you, especially if you have questions (provide as much detail/info as possible and pictures truly help)... With all the great folks here, generally someone will respond in no time at all. Please make yourself at home!
I'm sorry that you have lost your spouse. My sincere condolences. Even after 3 years, I'm sure it's still with you. It sounds like the lean to along the existing barn would work excellent as an enclosed run area. I have no idea what you have to work with as far as money or building experience. Perhaps you could hire an Amish person or handyman to enclose it for you. You could then frame up a shed sized coop with exterior door access at one end. Or just build a basic enclosure inside to give them a place to get out of the weather. The Amish also build excellent coops.
I would advise against a prefab coop like you see at
TSC. They are typically cheaply built with sub standard materials and as such will only last a year or two at most. They are better suited to emergency use for brooding hens, quarantine situations and similar. They are a huge waste of money better spent. Also, they will really only house 1/2 or less, the number of birds they advertise. A large fowl bird really needs ~4 square ft/bird inside the coop and ~10 square feet/bird in the run. These are recommended minimums. You can make a little less work with bantams or smaller birds or with large coops with lots of birds (They tend to flock/clump together, giving space for those who need it).
I hope things come together for you and that you'll share some pics as you progress.
Oh, if you haven't done so already, PLEASE put at least your general location in your profile. It could be very important if/when you ask for or offer help or advice. You know, climate issues and such. Old folks like me

will never remember & look there first. I recommend at least your state as we have a worldwide membership and that's the lowest level most can figure out. To add it, mouse hover over Account top right and a drop down will appear. Click on Personal Details and scan down. You'll see the spot for Location. Then go to the bottom and save changes. Thanks! Hope you enjoy the site!