Please post only 1 question in 1 topic. Thanks in advance.
1/ Theme Options > Header builder > Mobile menu > Select The Menu
2/ At first sight, your header fine – https://gyazo.com/c82cd46969507f9eda80c4b3b70c1fa5 Maybe you just need to clear cache. What exactly is not display proper?
3/ What exactly banner do you want to add? Go to pages > Edit the desired page > add/edit content depends on your needs. What issues with it do you face?
