Unsplash is an extensive image database that you can use to find images for your event page. You can use Unsplash in any place where you can upload images.
For example, to use the images from Unsplash in a gallery block:
Click on `Pages`
Click on `Start` or your event name (next to the house icon)
Click on `Gallery`
Click on `Add images`
Click on `Find in photo database`
You can then scroll through images and search for new ones in the search field at the top left.
Click on a photo that you want to use in Gallery
Click on `Use photos`