I have a pop up that says helperamc will damage your computer

You never need to download or install anything to eradicate something else you downloaded and installed. If you are averse to doing that sort of thing, continue below.

Removing "helperamc" and its ilk is simple and follows the general procedure described in Advanced MacCleaner popup virus - Apple Community.

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Navigate to the following folder, and post its contents in a screenshot:

~/Library/LaunchAgents

To open that folder, copy the entire line above and paste it in the Finder's Go menu > Go to Folder... field. Make it look like this:

... and click the Go button.

A Finder window will open. Take a screenshot showing all that folder's contents, and post it in a reply. To learn how to do that please read the Appendix in the following User Tip: Writing an effective Apple Support Communities question.

Usually, there is nothing in that folder so don't be surprised to find it empty. The reason for starting with that folder is to eliminate other potential causes before proceeding with steps that will identify and eradicate whatever is affecting that Mac.

There will be additional instructions to follow and this is just the first step.

For a description of how this may have occurred, how to avoid it in the future, and for Apple's recommended actions read How to install adware.

Review your Gatekeeper settings. To learn about Gatekeeper read Safely open apps on your Mac. Gatekeeper is designed to help prevent you from inadvertently installing garbage software.

Download and run Malwarebytes. Malwarebytes was developed by one of our own colleagues here in ASC and is about the most proven anti-malware software for Mac.