How can I see how much traffic is going to my site?

Gutensite and most other CMS platforms for that matter, does not track traffic data for hosted websites. If you'd like to keep track of your website traffic, I recommend setting up a free Google Analytics account and connecting it to your website. Gutensite integrated with Google Analytics to make it very easy to do so.

Take a look at this help article on how to set up google analytics:  Tracking Visitor Traffic with Google Analytics