Create a home page using asp.net sharepoint online

Hi,

We recently moved to sharepoint online and we have a requirement to add a homepage to be customized and shown as below.

I was able to create the above using asp.net, but the top part including the browse,page,home, design  etc are sharePoint i want the below part starting from welcome to be shown in the home page which i had developed in asp.net.  how do i do that ?