This is a collection of resources, most of which I reference in my "Design Systems: 0 to 1" talk.
Anna Cook has this excellent course on LinkedIn Learning about auditing design systems for accessibility. With recent legal challenges towards brands that have not made their products accessible, this needs to be part of your go-to-market plan for your design system product.
Nathan Curtis' overview on picking parts, products, and people for getting alignment at the kickoff of a design system project.
Design Systems Canvas (PDF, PNG, FigJam) https://www.designsystemscanvas.com
Sass Color Generator