Cannot Create Header

Site URL: https://shark-seahorse-nlrw.squarespace.com/config/pages

Hi

I am playing with Squarespace to see if I can recreate my Mum's website using their templates for her with a mind to moving there.

I am having a lot of trouble trying to create a header. Currently, the logo at the top remains and floats above the content below when you scroll down. This is ugly. I would like the header to remain as a "block" at the top and the content to scroll under it so it is hidden rather than have the content show through the block.

I have googled how to create a header, but there seems to be no way to actually do it. When I hold the mouse over the area that is supposed to bring up options nothing happens.

Any help would be hugely appreciated.

Thanks

Becky

Go to home page,  click on title not the gear icon,  page opens,  click edit page up in the top left corner, then you get a button for edit header. Click that then a window comes up on the right, choose style and enable fixed header. 

I found it under design>styles>header background colour. For some reason, when I followed the instruction to enable fixed header via the home page, I am unable to find any way to edit the header. But the way I found works so all good.