Hello, @Debbie292d has pointed you in the right direction with a link to the Learning Center. And you can always ask questions in the various forums, there are a lot of experienced members here to help you out.
Put ventilation in higher than where they roost and secure the holes with 1/2 inch hardware cloth
Make your coop and your run with a door you can walk into.
Space is very important - the more the better. Make your run big also and the walls 1/2 inch hardware cloth with an apron, and the ceiling solid or with 1/2 inch hardware cloth and covered in some of the run.