Could you please attached your site url so we can provide you appropriate solution.
We had gone quick look through the screenshot and we assume your header background color is dominating menu color. So it seems your menu to be hidden. So we recommend you to change color of menu container and menu. For this:
Go to dashboard -> Appearance ->? customizer ->Header setting -> change color from Menu container color & Header Navigation Menu Color options.
Also you can find many more options for this, please go through all the options.