Image Files
My favourite website for people to populate your renderings is Just Not the Same. http://justnotthesame.us/
Another great free source for more diverse, but not specifically black cutouts is Escalatina. http://www.escalalatina.com
Specialized in Indian cutouts and vector figures is Jugaad Render. https://jugaadrender.in/tagged/vector
Although they offer fewer POC, Mr.Cutout offers people in a wider variety of poses: https://www.mrcutout.com
Cut Out Life offers a wonderful multicultural selection: http://www.cutoutlife.com
Diaz Paunetto is kind enough to share the files that they use in office: http://www.diazpaunetto.com/people_png_cutouts.aspx
Cut Out Mix offers fun stylized options, which are more racially vague: http://www.cutoutmix.com/index.html
VECTOR FILES
Free, no strings attached vector silhouettes for your drawing sets: https://silhouette-ac.com/en
Also check out this "reference database of dimensioned drawings documenting the standard measurements and sizes of the everyday objects and spaces that make up our world.": https://www.dimensions.guide. They offer many DWG and AI files for free as well.
Vector Vault provides free vector drawings (available as both DWG and AI files!) of a diverse range of underrepresented groups. Over 140 original figures intended for student use are available under a creative commons license. https://vectorvault.webflow.io/