#unDraw is absolutely amazing for pretty much anything related to design!
https://undraw.co/illustrations
All the illustrations are free, you get SVGs, and you can even change the colour prior to download so they all have the colour scheme you want right ootb.
The license is even better. You can use them for free for both personal and commercial projects without attribution. I will likely give attribution anyway because it's just an awesome project but I do like the freedom they give.
I'm working on a talk for #SELF and this is the first slide: