I think the F-35B's can perform VTO but it's probably more practical to STO for fuel conservation & payload reasons.
On a mobile now but I'll link a video later where Lockheed was doing the VTOL/STOVL tests.
^^^This. VTO is possible, but the weight limits for vertical takeoff make it impractical for takeoff, but once the mission gas is used up, vertical landing is possible, in similar fashion to how the Harrier is operated. Hence, the current plan is for it to Short Take-Off Vertical Landing. Hence, the name STOVL.
To the OP, here is the basic plan:
USAF gets F35A - Conventional takeoff and landing on their cushy big runways
USMC gets F35B - STOVL, described above. Has a lift fan and rotating nozzle for low-speed flight to a hover. Intended to deploy to large "flattop" amphibious assault ships (LHDs). Yes, they have room for a short running takeoff.
Finally, Navy gets F35C - Carrier variant. Works basically like any other Navy jet for launch/recovery.