I would suspect there are lots of tutorials on youtube on this
Intro to matrices
https://www.youtube.com/watch?v=yRwQ7A6jVLk
It probably depends on your prior learning which tutorials are more suitable.
Ah, no problem, I am not teacher, but understanding your own learning style(s) is a really important first step.
As you are learning this for game design it may be worth reaching out to the
@godotengine as they may be able to suggest specific learning materials that apply matricies to game creation.