If you are getting notifications from FreshSkill, then your Mac is infected with adware. FreshSkill is adware for Mac.
FreshSkill changes setting in your Mac. First, FreshSkill installs a browser extension in your browser. Then, after FreshSkill hijacks your browser, it modifies settings in the browser. For example, it changes the default home page, modifies search results, and displays unwanted pop-ups in your browser.