Hi Kari! I'm in the same situation as you, but I'm converting a large shipping crate to a coop for my 13 hens.
We have no carpentry skills whatsoever, but are making slow but steady progress. The windows and french door are in, and today we put in the roost, poop deck and a chicken tunnel (Chunnel) to connect the pop door to our hoop coop - which, BTW I got on CraigsList for $175 and yes, the materials would have cost double that. So that rude person who contacted you was quite uninformed.
Back to your question, I read one BYC'er who recommended Valspar Barn Paint. Lowe's carries it and I bought some today for $22/gallon. It comes in both red and white, is self-priming, safe for livestock and, according to the OP, covers in one coat. They recommended using the oil based rather than latex version since it's so much more durable and said just to use a disposable brush and roller, and you're done!
I was going to use ooops paint (mistinted) but finally decided it was worth the $$ to get the barn paint since I wouldn't have the extra step and cost of priming nor have to put on multiple coats for even coverage.
And if you don't want red, another BYC'er swears by Urethane deck paints. No primer, high solids which means high gloss. Any color you want and last forever. It's what they put on porch floors so $35 a gallon and one gallon covers 350 to 400 sqft. One coat and impervious to water. OK, actually on raw wood one coat will only cover about 300 SQFT, second coat if ya want one covers 400 SQFT. Yes, it's oil based but all good, one disposable brush and one roller cover your throwing out after. (sorry, but I don't know who originally posted these recommendations...)
I wish you all the best with your deer blind coop and you MUST post pics when you finish - i can hardly wait to see it! I'm sure lots of people could use the information and be inspired to try it for themselves!