Removing 'sub headers'?

I’d like to remove the additional headers in my main page – on top of the main post area and on top of the sidebar. I’m not sure what exactly they are called, but they are the sections in my site with the text “THE KIWI FOODIE” and “FOLLOW”.

Also I’d like to be able to change the main header text to dark so I can use a light header background, and change its font type… what custom CSS should I use for this?

Thanks!

https://kiwifoodie.co.nz/