Welcome! Whatever you decide to start with, (I would suggest 5-10 maybe with a nice big yard like that) I would suggest building your coop for more than you think. Chicken math takes over and you always end up wanting a few more.
Watch out, it is addicting. I started with 6 pullet chicks from local feed store in May. In July I added a cockerel that is 4 weeks older then the pullets. I just got 3 one day old chicks from the feed store last week. And I will be ordering 10 more chicks in the spring(for bantams and LF breeds the feed store does not carry). Then after that whenever I get a broody I will let her hatch out a couple of eggs and raise them. So yes, get a few but build for many. I have a 12x16 coop and just built a 4x4x10 tractor/grow-out/broody coop. And I only have 3 acres. HAHA. Have fun