Spaceing between Title and Body of text

Maybe this will help:
https://presscustomizr.com/snippet/change-grey-bar-navbar-slider/

I am not sure, but I would just try to add a margin-bottom for the first part of your question. So it would be something like

header.tc-header {
border-bottom: 2px solid green;
margin-bottom: 100px;
}

to add to your child-theme’s CSS.