Who knows how to edit CRM VTIGER?

Question

CRM

I'm sitting like this and it's bombing me, how can I start editing something in this "CRM"? You can’t really change the menu in the settings, you can’t change the theme ... There is some kind of house in the Code .... I can’t find a certain sequence ...
Who knows some good article about vTiger or maybe there is an opportunity to download somewhere "Empty "v Tiger?

Answer 1

Indians know
that there is an empty one, it is open source
https://www.vtiger.com/open-source-crm/