
Thomas S. answered 04/19/19
MFA in Studio Art and Visual Communications which covers design.
Understand the source you are getting your photos from. If you go to a site... let's say the Smithsonian Image collection... then some of the images may be public domain/open source (free to use for everyone) or not.... If you cannot easily find out then you would have to use the contact feature usually found on most sites to contact them which could take forever, or you could easily just not hear back from them ever. You can also look at their terms of use info if listed - which the Smithsonian does.
When in doubt about this it is probably better not to use the image/s if you don't want to infringe on copyright or get in any kind of potential trouble.
You can of course try to find applicable images on open source image sites. Just google open source images/photos and you should have lots of options.
https://abovethelaw.com/2018/07/using-online-images-without-violating-copyright/
Here is a little online article about this issue.