Working on my first plugin, need help with direction

Hey guys,

I want to create a simple form creation plugin(that is specific for my CRM, that’s why i want to create one). The idea is having a “add input” button which lets me chose the type of the input(text,phone,email,checkbox and etc), after I finish adding the input fields I click ‘save’ and it creates a shortcode as well.

I guess it should be some sort of custom post type because I want to keep a list of all the forms I created with the ability of editing them.

I need your guys help with the workflow, on understanding what I need to search for to create this.
I tried looking at plugins like Contact Form 7 but I didn’t understand how it works.