Here are some useful links for commercially free cliparts

Clipsafari:

https://www.clipsafari.com/

Freeimages
(select Free clipart:

https://www.freeimages.com/clipart

Friendlystock.com - Free clipart:

https://friendlystock.com/free-clipart/

Pixabay - Illustrations:

https://pixabay.com/illustrations/search/

Uxwing.com":
(Free icons)

https://uxwing.com/