Hello
1) You should prepare your own header image, size is 2437 x 113 px, name it as sky_bg.jpg (or sky_bg2.jpg if you use style 2, or sky_bg3.jpg if you use style 3) and upload to /wp-content/themes/wp_hot_churchly/images/custom (overwrite existing). Regarding the footer, prepare image of size 1920 x 494 px, name it as woon_bg.jpg and upload to the same folder.
2) You should edit background image image /wp-content/themes/wp_hot_churchly/images/custom/topmenu_bg.png. After that, you should edit background colors theme options, tab Menus Settings > topmenu
Regards
Milos
