do i need to clear junk files from macbook air

I would not remove any files that CMM says you should.

CMM is considered by many veteran Mac users to be junk itself. It's unnecessary on the Mac. Apps of the types clean-up, anti-virus, optimizing and VPN often create more problems than they solve. It's best not to install any of these. The macOS is very secure and capable of taking care of itself if you simply keep it updated and reboot from time to time.

The first rule in keeping your Mac running smoothly is simply: don't install junk.

CMM is junk and you should uninstall it as per the developer's guidance.

https://macpaw.com/support/cleanmymac/knowledgebase/uninstall-cleanmymac

Self-inflicted malware can be a little bit of an issue, but that can be avoided if you follow some rules for safe computing. For more info, please see these support documents:

• Effective Defenses Against Malware - Apple Community

• Avoid phishing emails, fake 'virus' alerts…and other scams - Apple Support

If you are having some problem that prompted you to consider and install CMM, please feel free to elaborate here in the Community and let's see what we can do to assist without junking up your Mac.

Etrecheck - the handy reporting tool for … - Apple Community

is a great utility to identify what may be junk on your computer, and is not, without actually cleaning it.

The report it generates can be shared with the community if you need guidance.

And I agree CleanmyMac, MacKeeper, or any "cleaner" utilities except an actual AppCleaner are pretty much junk.

https://freemacsoft.net/ and their AppCleaner is a smart uninstaller that lets you drag an App you don't want anymore over its window and clean out all the dependent files on it. Unlike some other app removal software, it doesn't require being installed prior to the app's installation.

Any program which affects system level caches, prebinding, should only be used by experts on systems that are fully backed up.

wad001 wrote:

I have installed clean my mac x but have been reading I shouldn't have and that I don't need it...do i need to remove junk files etc that CMM says it does?

Uninstall CleanMyMac and all other third party apps that claim to clean, protect, manage, boost performance, etc. Such files use system resources while providing no benefit. They are not needed and they may cause problems.