Most major pharmacies carry the vaccines. Please check with the specific location to determine which manufacturer’s vaccines they offer.
Maricopa County keeps a calendar and list of providers and locations: https://www.maricopa.gov/5659/COVID-19-Vaccine-Locations
Please be aware that the Pfizer pediatric vaccine for kids ages 5-11 is only offered at select locations. Make sure to specifically search for Pfizer (5-11), to find locations which offer the vaccine for kids 5-11.