Build User Activity Tracking Website

I want to build a website. The website will offer a service to its registered user for free. The service is to track their website visitors' actions. In the backend, there will be various triggers related to the actions. If a user takes an action like filling a form or clicking somewhere, a javascript function will be executed in the browser which will call AJAX method and a "trigger" code linked to that action will be executed in the backend. Triggers can be sending an email or changing a field of the customer profile. A user can configure actions and triggers in the backend using a simple interface. If this is the action, this will be executed. You will need to design the public website (for marketing), customer dashboard (where customers can create actions and triggers) and the admin website (where I can see all my customers who are registered [with some basic statistics like how many are registered]).