Unfortunately the wiki pages like https://www.inaturalist.org/pages/help are not crowd-translatable. You can send them to the help page(s) of network member sites in Spanish-speaking countries:
www.naturalista.mx
columbia.inaturalist.org
ecuador.inaturalist.org
argentinat.org
As for videos: some of the videos have Spanish subtitles, you just need to click on the CC logo:
I made a tutorial for creating video subtitle files: https://forum.inaturalist.org/t/how-to-make-subtitles-for-inaturalist-videos/7667