Hello and welcome to BYC! Glad to have you here!
I would definitely recommend at least three if possible. I lost more birds than I expected in my first year of raising chickens. It's definitely worth it, though! I highly recommend getting a good predator-proof coop set up from the start to keep them safe. My coop has a wood frame with hardware cloth running under the ground all the way around it to prevent digging, a solid roof, carabiners to go in all the latches to stop raccoons from opening them, and hardware cloth in all the windows so that they can be opened for ventilation as needed. I suggest a ground coop rather than a raised one. Mine is raised and it is definitely inconvenient at times.
Best of luck with your plans!