Hello,
Your first question is not clear. I will try to guess. If you mean shop page with the list of categories in the heading http://prntscr.com/k2tnod, you can change the background image/color in the page settings. You need to enter shop page editing mode and you will find the settings: http://prntscr.com/k2toey
The second question.
1. Find out which menu has been used in your header:
Please navigate to Woodmart > Head builder http://prntscr.com/iyd2pe
Choose the proper header type (your current) http://prntscr.com/iyd333
Find menu and check http://prntscr.com/k2tpk8
2. Navigate to Appearance > Menu > find this menu and edit.
Best Regards
.
