easiest way to do this would be to write it in to the footer, then it will show on every page.
create an over ride by downloading tpl_footer.php from includes/templates/template_default/common
then upload it to includes/templates/your_template/common
your_template being the name of template you are using, if there is no common folder in includes/templates/your_template/ create one and add the tpl_footer.php into it
open the tpl_footer.php and add in this code just above <!--bof-navigation display -->
<div id="fti">
<p><?php
echo "your text here"
?></p>
<img src="your image file path here" />
</div>
change your text here to what you want that to say, upload your image to public_html/images and change your file image path here to images/picture.png
picture.png being the name of the image you want to use, this can be a jpg or gif or what ever you want to use, jpg tend to be a good choice though, make sure the end of the image reflects the type of image you are using, .png or .jpg or what ever type of image it is
then go into includes/templates/your_template/css and open stylesheet.css and at the very bottom of the page add this code
#fti img {
display: table;
margin-left: auto;
margin-right: auto
}
#fti p {
display: table;
margin-left: auto;
margin-right: auto
}
this will show text and an image just below the text, centered on the page, all of which will be above the footer content
you can add extra styling to the text by adding this extra code into #fti p {
font-size:12px;
add that above the last curley bracket } and change the 12px to a size you want,
if you want the text to be bold add this
font-weight: bold;
add that above the last curley bracket }
save all the changes and upload the stylesheet.css to includes/templates/your_template/css
and save all the changes to tpl_footer.php and upload that to includes/templates/your_template/common
thats a really simple way to do it and should work perfectly
if anything goes wrong, just delete the tpl_footer.php from includes/templates/your_template/common and everything will revert back to the way it was before any changes were made