FYI, that coop has been posted here several times and I don't think it's nearly as large as folks think it is. For 8 chickens you'll want roughly 32 sq ft of coop floor space. The enclosed part of that coop is maybe half that. You can make alterations to try and make the entire unit work as a coop though, and then add a properly sized run (80 sq ft+) to compensate.
See this thread: https://www.backyardchickens.com/t/1168505/build-a-bigger-run-or-free-range - I'm pretty sure that's the same coop as the one you bought.
See this thread: https://www.backyardchickens.com/t/1168505/build-a-bigger-run-or-free-range - I'm pretty sure that's the same coop as the one you bought.