これとか？
https://docs.godotengine.org/en/4.0/tutorials/math/vector_math.html#normalization

後はVector2かVector3のクラスリファレンス見るの良い
https://docs.godotengine.org/en/4.0/classes/class_vector2.html#class-vector2-method-normalized
https://docs.godotengine.org/en/4.0/classes/class_vector3.html#class-vector3-method-normalized