Somewhat dependent on where you will be living in Mesa, but check out:

https://www.bicycleranch.com/articles/group-rides-pg178.htm

They are in Scottsdale and have 3 different groups, A, B, and C for different ride cadence.  I would ask them for recommendations in Mesa.  Scottsdale is a very common riding area- bit less traffic with ample bike lanes on LOTS of roads.