Thank you very much, I made progresses.
I still have some questions:
1) I woud like to keep the default menu icon (the three lines), I only would like to change its color in white, could you please tell me what is the right code to paste?
1b) How to set the color of the icons (menu, search, account user, cart) in white also on mobile version?
2. About the map, I do not know what is portrait mode or landscape mode. Could you please give me some pratical instruction to make the map look good on mobile?
3) How to set 3 or 4 column of products instead of 2 in the page?
thank you a lot for your help