To best utilize the site you need 4 images:
Your logo (overlays on header image)
One large “header image”
Two small square images.
You must have all of the above OR just one single small image. It is suggested to use photos without any text on them because they resize depending on the device used.
Image Specs and Templates to Use:
Canva Template for Header Image
(1600 x 950px):
https://canva.link/cez2mj09egr8qno
Canva Template for Small Images
(600 x 500px):
https://canva.link/8ey3vzag6mpo48m