I need a consultant for mac

We have three Imacs and two laptops that need to be cleaned up, Ram upgraded, one or two possibly replaced. We need someone who can adjust settings to what we need and figure out problems - in person in Brentwood. We also need to upgrade wifi so it reaches our whole condo well - we already have an older mesh system and are on 400 mbps on Spectrum and some parts of the condo are spotty.