Congratulations on chickeneering!
Build FAST! Chicks at 2 months old are pretty big already -- about 3/4 their growth already.
A minimum formula for coops is to have 1-sq-ft per each chicken open ventilation near the roofline, 4-sq-ft per each chicken coop floor space, and 10-sq-ft per each chicken open run/pen space - these are minimum for chickens' health and well-being.
Make a door big enough to enter the coop for cleaning. Our first coop was only 41/2 feet tall and hard to hunch over to clean it.
So glad to hear you're having chickens. You have a nice assortment of equal-sized breeds and hold-your-own temperaments. Docile breeds would be too timid in your egg-laying group. I think you made good choices - they are all brown egg-layers but after a few times of collecting eggs you can figure which hen layed which egg as shapes and color-shading will be a bit different w/ each hen.
You must post pics of the chicks and your coop development and first eggs! There's a BYC thread called "post your chicken coop pictures here" where you can share your coop build.