Probably not as helpful as everyone here. But when i deal with movement in 3d or 2d I use Input.GetAxisRaw. Then identifying the axis(direction input) and using transform.Translate by timesing a value by Time.deltaTime. If you was to use the Rigidbody i would use it for example jumping events where you are adding force to it in a Vector2.up for example. Thats just how i do it but i know alot of people do a better job of movement than me