You can integrate analytics as well as disqus chat into your site in your system settings under Integrations.
To add analytics to your site click on the type dropdown and select either custom or google analytics. Then a box just below that will appear. If you have google analytics you should be given an Id number which you will use to link your website to google analytics. For custom you will drop in the code that you are given by your analytics company.
Disqus allows your users to leave comments on your pages and creates an active community on your website. In order to use this you will need to go to disqus.com and create and account and then add disqus to your site.