Godot has one of the better explanations of vectors and their uses in games in their documentation, if you haven’t checked that out yet. It focuses on their practical use rather than going deep into the mathematics (though there is quite a bit of that too).
And if you don’t understand the math, the documentation also explains when and how to use specific methods, so you can still use it as a cheat sheet when working on your project even if you don’t fully understand vectors.
(And you’ll probably have an “ah-ha!” moment when working with them yourself. Like a lot of math, vectors are much easier to understand with practical, non-abstract examples.)