If "nothing" happens when you turn the key, then you are probably still asleep in bed

If you turn the key and your ignition lights come on, but the starter doesnt turn, then look to the small spade connector on the starter motor.
If you turn the key and your ignition lights come on, and the starter clicks then look to the earth on the gearbox and the engine.
If you turn the key and your ignition lights come on, the starter does turn, but the van doesnt start then we need to know what engine you have.
It may also be the ignition switch, so you could try a voltmeter on the small spade connector on the starter motor to see if it is getting voltage.
Also worth giving the starter motor a good bang with a wooden mallet.
T
There are 10 kinds of people. those who understand Binary and those who dont