Basic Front-end changes to PHP web project (WE TRANSFER)

My Start-Up project is an alternative to WeTransfer.
The current look and function are almost the same as WeTransfer.

First step:
Due to lack of time, I need help with some basic changes that will improve the UI, such as:
Add Header, Footer, New Pages ...
Change the interface in the field for importing files and emails ... change the admin URL ...
Improve mobile responsive ...

PS: There is an option for long-term cooperation.