Problem removing the navigation header (Home>Subject)

Please provide a link to a page on your site where we can see this. Thanks.

.page-header {
  display: none;
}

To add CSS: use the “Additional CSS” option in the customizer. https://codex.wordpress.org/CSS#Custom_CSS_in_WordPress

Learn to use the Chrome Developer Tools to help you see and test changes to your CSS.

I recommend asking any additional questions at https://wordpress.org/support/theme/profit-lite#new-post so the theme’s developers and support community can help you with this.

.main-container {
   margin-top: 0;
}

To add CSS: use the “Additional CSS” option in the customizer. https://codex.wordpress.org/CSS#Custom_CSS_in_WordPress

Learn to use the Chrome Developer Tools to help you see and test changes to your CSS.

See https://cldup.com/u_UNHwGrvVr/SA6jhL.png