Description of the findfree3d (FF3D) site :

https://www.reddit.com/r/Cinema4D/comments/1h81n40/made_a_tool_to_find_free_assets_on_all_major/
https://findfree3d.com/

Be sure to drag it under down to site before using it!
Instructions are included!

and I did a search on
ChatGPT(https://chatgpt.com/) and the Gemini(https://gemini.google.com/) site for

1. 3d asset keywords
2. I'm trying to search for 3D assets, but I need to know all the “keywords”!

There are many other ways to find search terms. Give it a try!