Adding web analytics to your site helps you to do the following:
- understand and analyse your web traffic;
- re-target users who have visited your web site in marketing campaigns.
We recommend that you at least implement Google Analytics and Facebook Pixel on your site.
- How to Add Google Analytics to WordPress. This document provides good introductions on Google Analytics, steps on signing up and instructions on adding the Global Site Tag (gtag.js). If your site is based on WordPress, you can install Google Analytics with a WordPress Plugin. You can choose from many similar plugins available in the market (mostly free).
- How to Share Your Google Analytics. You can share your Google Analytics with someone without giving them access to your own Google Account. Likewise, if someone else has set up Google Analytics on your site, you can request them to give you access.
If you need to insert many different analytic codes to your site, you may consider using Google Tag Manager. For more info, you can read this: What is Google Tag Manager and Why Use It?
This document from Facebook provides excellent introduction and instructions: Create and Install a Facebook Pixel