how to make characters move in unity code example

Example 1: unity move with rigidbody.moveposition

rb2D.MovePosition(rb2D.position + velocity * Time.fixedDeltaTime);

Example 2: how to move a 2d character in unity

if (moveInput != 0)
{
	velocity.x = Mathf.MoveTowards(velocity.x, speed * moveInput, walkAcceleration * Time.deltaTime);
}
else
{
	velocity.x = Mathf.MoveTowards(velocity.x, 0, groundDeceleration * Time.deltaTime);
}