I have a MacBook Air. Do I need McAfee

The findings on this forums have shown a connection between Anti-Virus Packages for OS X and direct conflict with OSX's ability to protect itself. The best software solution to protect your Mac is keep your OS up-to-date from Apple, and avoid AV and Cleaning packages for OS X.

No!

Nope'

No to both them. They are both crapware that does far a lot of harm and no good on a Mac.

You have already been provided excellent advice. Mac OS run's best if simply kept up-t0-date and otherwise left alone. It does not require antivirus, cleaning or ANY third party "maintenance" apps to run well. If left alone and kept up to date you should anticipate years of trouble free operation.