Changing font and size of tagline??? help

You can change it in the style.css file in this code — line 300:

#site-description {
    color: #B14562;
    font: 13px "Sorts Mill Goudy",serif;
    margin: 0;
    padding: 0 0 0.8em 1.9em;
    text-transform: uppercase;
}

These pages may be helpful too:

https://codex.www.ads-software.com/Playing_With_Fonts

https://codex.www.ads-software.com/CSS