If you want to practice hovering, do not put anything under the wings and don't load ammo. That will let you take off and land vertically, but the Harrier is highly unstable in hover mode (seriously, it's worse than almost any helicopter).
On an ordinary mission you can't really take off vertically since you're too heavy, but after expending the ordnance and burning some fuel you might be able to land. That's a good way to fail a mission, unless you do a helicopter-style landing: simultaneously slowing down and descending while keeping your eye on a spot on the ground, going into hover a metre above the spot for a second and vertically descending onto the concrete.
That as well. Thrust vectoring is of little use without the thrust.