learn to eliminate MacBook Air security vulnerability to security threats

Big Sur MacBook Air 2013 intel. It appears that for quite some time, longer than I can track back to but starting potentially from July 2021, until today, my accounts have been manipulated. I believe there’s potentially a moll in my computer altogether but certainly there was one in my Google accounts. I would like to hire an ethical hacker to help me eliminate security vulnerability with respect to my devices and accounts. My iPad has been an unavailable status since September and how is it logging in to google in December with the status of the device displayed on the screen being unavailable since September? . This is only one example.