I've always used https://www.svm-tutorial.com/ as my go-to suggestion for reading up on SVMs as it starts easy and progressively adds the complexity as needed.

> This tutorial series is intended to give you all the necessary tools to really understand the math behind SVM. It starts softly and then get more complicated. But my goal here is to keep everybody on board, especially people who do not have a strong mathematical background.

Emphasis mine.