Mobile menu order & Featured Image

Hi all,

Hoping someone can help me. I am doing a site for a friend and I have two issues, I have spent days trying to figure it out so you lovely people are my last resort!

I have two issues, firstly I am not using the default menu at the top, I have hidden that and I am using a menu in the sidebar to navigate the site. However in mobile view this menu appears at the bottom and I need it to appear at the top.

Secondly, in the standard desktop view, I would like the featured image on the top of each page to span the entire width and for the side bar to drop below this image and start to the left of the actually content of each page.

You can see the site here (not finished yet).

Thank you in advance.

Lee