Don’t worry Jordi we are all learning here.
To leave space between menu and the image try this. Go to “Appearance > Customize > Element Spacing” and then see if you have “0” (zero) under “Separating Space”. If you have zero there set any number and see if it has any effect,then you can adjust that number as you wish.
Sorry if that doesn’t work for you,i’m sure Tom will provide a solution we can all learn from.