Gear lever come very lose and can not get gears

Hi
It sounds like the gear lever has dislodge from its housing.
If you remove the gaitor which covers the housing you will see clearer.
The gearstick will be held in place by one of a few different methods but it should be easy to see.
It will be something along the lines of a ball and socket which is held in place by a spring loaded coupling, or could be a splined shaft which is clamped together, or a roll pin holding it together.
Failing this it could be that the actual gear lincage has come away under the car where it connects to the gearbox (again a splined connector) which would need re-alighning then it is held together by a clamp with a screw and nut.