Do I need to install virus protection?

No. AV software for Macs are scams. They are worthless. All they do is use computer resources to cause problems on your Mac.

No you do not, Mac's don't get viruses like windows and need to better explain what is happening...

Chances are you have downloaded some sort of malware or adware.

To check your system for bad third party software and malware you can safely run both Etrecheck and Malwarebytes on your Mac.

Don't install anything at all. It's best to describe the problem in as much relevant detail as possible, rather than what you think is causing it or how you think it should be solved.