If you are tasked with Creating a PPT/Video/Poster, the main ingredient would be high-quality images. Downloading images from a google search would lead to copyright issues, Blurred / Watermarked images, and many other issues. There are a few websites online where you can download HD Images for free. I have listed a few in this below.
Unsplash is a website dedicated to sharing stock photography under the Unsplash license. Since 2021, it has been owned by Getty Images. The website claims over 265,000 contributing photographers and generates more than 16 billion photo impressions per month on its growing library of over 3.48 million photos. Unsplash has been cited as one of the world's leading photography websites by Forbes, Entrepreneur Magazine, CNET, Medium, and The Next Web.