If you imported a sample homepage and had some sample promo banners, you only need to enable the builder then edit directly on the frontend.
On Home page builder, click
Add New Block button.
On popup list blocks, click
"Promo Banner" item.
BANNER CONFIG TAB
Here you can setting some general options for your banner as
general color, background color or image and some other settings, just select and experience
Here you can
upload banner image, set url when you click on the banner, add text to banner, add button, adjust text's position, color of button,....
After completing your banner, just click
Submit button to save your banner