Hi Craig Chalmers,
If you are using shortcode for form , first you need to find wrapper ie. id or class of form add this css in child theme[style.css]:
#fr-banner #id or .class of form {
position: absolute;
margin-top: 5%;
margin-left: 65%;
}
Note: Ajust margin-top and margin-left value as per your requirement
If you are using form html , then just wrap with some html tag element along with specific id or class. and then take those id or class to make them overlay with banner image.
#fr-banner #id or .class of form {
position: absolute;
margin-top: 5%;
margin-left: 65%;
}
Don’t hesitate to ask a question if you got any doubt on this and also you can see the article as a reference Reference example on how to overlap html elements?.
Note: please add those css on child theme style.css file so your changes will be lost on theme update.
Thanks