Change a templatedwebsite into a real Website with added functions

Take my templated site and convert into a website that I have more control over meaning dd additional functionality. I bought a templated site but was not told I cant change anything. I own the domain name. Problem, the site is a template and I have no access to source code. I can’t change password if I forget. The Tabs (you will see when I select the right candidate) are generated by three companies who have given me an affiliate link, co branded links, these need to be replicated and I don’t know how to do it, I can’t see how the past developer added these nor can I see where my affiliate links are embedded. Admin Password Master change, if lost I need all back doors to the template locked. Add Permissions for the blog only, so I can get a guest writer to add content, keep the same lay out but enable meta tags, image tags. Problem: Site, each page I should be able to Add Meta tags and where there are images, image title tags. I should be able to add footers Add A Page and auto Adds the page Navigation Tabs Each page, including existing I should be able to add Meta Tags including image title tags. Font, style colors should remain the same. Blog, can remain the same but I want to add share options, Id also like to be able to auto post on facebook including the images. I need some one to Integrate email sign up template with my mail chimp account. Most of the work involved is copying what already is there, I love the look colors and fonts, just need more control.