Does Apple give you a toll free number to call about possible viruses?

Any popup message you see regarding a possible virus, will be a scam. Do not respond.

There are no known viruses for Macs. There is adware and malware. For adware, those things that keep poping up in your browser you can use AdwareMedic from thesafemac.com to quickly and easily remove all know adware.

That site also have this Adware Removal Guide if you prefer to do it manually thru the Finder.