I suggest taking the plastic off the coop to allow better airflow.
Instead, use a tarp to make a side wall off the frame that's supporting the cover. Not closing it off completely, but just blocking the wind/rain in the area next to the coop.
If you have minimal tools and minimal woodworking skills then a hoop coop is the easiest build and the cheapest in material costs.
https://www.backyardchickens.com/posts/23607034/
This one doesn't use wood at all, just the cattle panel, the t-posts, and wire with tarp and pallets:
The Usual Guidelines
For each adult, standard-sized hen you need:
4 square feet in the coop (.37 square meters)
10 square feet in the run (.93 square meters),
1 linear foot of roost (.3 meters),
1/4 of a nest box,
And 1 square foot (.09 square meters) of permanent, 24/7/365 ventilation...