mobile reduce whilte space between rows

1. To hide the secondary navigation on mobile, you can do this:

@media (max-width: 768px) {
    .secondary-navigation {
        display: none;
    }
}

2. The spacing below your logo is because of this custom CSS you added:

@media (max-width: 768px) {
    .site-logo {
        margin-bottom: 20px;
    }
}

3. The spacing in the content is caused by VC - you might want to check with them/your settings to adjust those values.

For example:

@media (max-width: 768px) {
    .vc_row-has-fill>.vc_column_container>.vc_column-inner {
        padding-top: 0;
    }
}

The spacing below the title is caused by this element: uvc-heading-spacer