If you are use the Elegant Themes Foxy template and wish to have custom slogan on the right you can by adding this below.You will need to edit header.php of your theme files below:

Find this:

<p id="slogan"><?php bloginfo( 'description' ); ?></p>

And replace with:

<p id="slogan"><?php bloginfo( 'description' ); ?><br>
<span>Your custom slogan</span></p>

To make the menu and tagline, you may need to toggle the below values that should be added to custom css in theme menu.

 #slogan {
padding-top: -2px;
position: relative;
left: 60px;
top: -80px;
}

#top-navigation {margin-top:-65px !important; margin-left:60px !important;}