General information about Trackers and Tracking Cookies:
The Guardian has some interesting reading about trackers and tracking cookies.
Yes, the Guardian article is from 2012 and these technologies have evolved and become more sinister and secretive.
HowToGeek.com is a very reliable web site with all sorts of good how-to advice. Their article from 2016 The Many Ways Websites Track You Online is worth your time.
But if you want a shortcut without the background knowledge then go and install in your Firefox web browser the extension named DuckDuckGo Privacy Essentials.
Here are four more articles from well reputed sources about this extension:
Stay safe!