Pixabay offers a curated collection of copyright free images and videos, which are safe to use for personal and commercial purposes with no attribution required. There are a variety of search filters, including file type (photos, vector graphics, illustrations, or videos), orientation, category, size and color.
To download an image, first click the image from the search results to go to that images download page. Click Free Download, select your preferred file specifications and click Download.
Verify you are not a robot and click Download again. If prompted, select the desired file location and click Save.
Here is a sample of some of the images downloaded, added to a PowerPoint slide and stylized: