Change design of Wp event+ plugin with CSS coding

Hi,

I am using the Oxygen builder with the plugin WP Event+. THe plugin is already setup and configured.
I would need some design changes (font,colors ect) on the plugins elements. Also need the elements to be contained as fullwidth page max 1400px on dektop (now it full width), and need to add padding/margin in the top and buttom of the pages containing the plugin shortcode. All design need to be responsive of course.

Please let me know if you have experience with the WP Event+ plugin or Oxygen builder.