Well, there's nothing in StaticBody called "Translation". There is a property called
translation that represents the body's position in local coordinates. It's not a function though, so
() would not be appropriate the second time you write it.
Also, there's no
position property in 3D nodes either. What you really want, to tween the position from its current value to an offset of (0, 5, 0) would be
translation + Vector3(0,5,0),
null here just tells the tween to use the current value of the property as the starting value.