How do I get clip art into a writer document? Where do I find clip art?
There are many licence-free clipart sites. Clipart is not part of LO.
There are some extensions that add clipart to the gallery. Go to the LibreOffice Extensions site and search for gallery, there are the old clipart icons that were in v6.x LO as well as some others.
Note: The one called “OpenClipart.org integration” hasn’t worked for a while but you can just go to https://openclipart.org/ and search on that site, download your choice and Insert into Writer. Cheers, Al