Problem at the top of the page

Could you be a little more specific? Do you mean the top blue border?

If you mean the top blue border, it can be disabled from theme options. “Disable top border” or something similar.

If you mean the grey line between the logo and the slider, you need to add this to your custom css panel, in theme options:

.tc-header { border-bottom: 0; }

I misunderstood,

It was the space for the teg line & social media links.

Incidentally, is there a way to remove this row completely?

Thank you for your help

Try this snippet.

To remove both, use:
.navbar-wrapper .navbar h2, .navbar-inner .social-block {display:none;}