Lead Developer
Hi Paul,
You can take a look at our child themes to see how to add a sticky header – it involves enqueuing a javascript file, and then including some CSS to make it stick.
Take a look:
https://wordpress.org/themes/exhibit
https://wordpress.org/themes/mantle
You’ll want to copy the enqeueue part of the functions.php, and also make sure to download the file it’s enqueuing.
Then copy the CSS dealing with “stickynav” and you’re good to go.
As for the image – if you don’t want to hardcode the text into the image, then you’ll need to set the image as a background image so the text lays over top of it.
Let me know if you have any questions 🙂