You'll find that the kinematic functions are the same:
move_and_slide(), etc., and work in much the same way. You'll be using Vector3 instead of Vector2.
However, being in 3 dimensions does introduce an additional level of mathematical complexity, especially when it comes to rotations. In 2D, there is only one axis of rotation, while in 3D there are infinitely many.
Your object's position/rotation/scale are stored in a Transform, which contains an
origin (location) and a
basis (rotation/scale). You'll use the
transform.basis to get the object's local axis vectors. For example, the forward vector of a 3D object is
There's a good overview doc here: https://docs.godotengine.org/en/stable/tutorials/3d/using_transforms.html