How to Edit the Call-To-Action Box?

I’m using Doover Version: 2.1.2.

On both visual and text editors, I can see the following shortcode:

[row]
[box_call_to_action title=”Do You Want To Be In-Sync? Just Hit The Button” style=”contact” btn_title=”DEMO NOW” link=”https://xxxxxxxx.com/signup”%5D

[/box_call_to_action]
[/row]

I want to replace the button with another one, but I can’t figure out. I know I can add an image and just link it to a webpage, but this is not how I want it to be done. I want to know how to edit the shortcode. Moreover, it would be very nice to learn how to add and edit any shortcode. I don’t know anything at all about CSS and PHP, but I have a basic understand of HTML.

Thank you very much in advance.