What causes my bike to shut off when I push the clutch,like turning the key off ,h

Here are some possible causes:

Low idle RPM: If your idle RPM is set too low, the bike may shut off when you put it in gear. You can consult a manual to see what the RPM should be.
Side stand switch: Most bikes have a safety switch that shuts down the engine if the side stand is still out. Check if the side stand is still out and if it is, try putting it up.
Clutch lever switch: Most bikes have an electrical switch in the clutch lever as a safety feature so that you can't start it in gear unless the clutch is in. This switch could be faulty.
Safety control box: This box checks all the safety features and kills the engine if needed. It could be faulty.
It's best to take your bike to a professional mechanic who can diagnose and fix the issue for you unless you can check off each of the above as the problem. https://www.manualslib.com/manual/833178/Yamaha-Xvs650.html

A Sticky clutch springs to mind in that scenario.

Engine off
Put bike in 1st gear
Pull the clutch in

Can you push the bike forwards?

You can also try running the bike on tick over until the bike is fully warmed up to heat the clutch plates.

No key?
You would need to hotwire the ignition. If you got caught with a hotwired bike the cops would start to ask hard questions.

No Kick start?
If it has a manual clutch you can turn the ignition on put it into second gear run push the bike up to running speed jump on it and release the clutch quickly to engage the engine.If its a centrifugal clutch (twist and go!) you cant bump start it.

But reading your question, I would ask whether you scooter is road worthy. Running and jumping on a moving bike with live electrical cables hanging out of it in a fuel rich environment is probably not a good idea!

If the clutch is not engaging you may need to adjust it or it may be deflective. If the clutch is holding enough to cause the engine to rotate when you push the bike in gear it may still not be able to hold when the engine is running.

You need to put it into neutral in order to start it or pull the clutch and hold it down until started. I would suggest putting it into neutral. Double check that you have it in neutral by trying to push the bike without holding down the clutch when you think you have it in neutral. If the bike rolls easily, then you know its in neutral. If it won't push or seems hard to get it to roll forward then you know its still in gear. Once you have it in neutral (for sure), hold the clutch down and start the bike.

Othen than that, all you have to do is make sure its turned on and it should start. Some bikes use a key to turn it on, others have a throttle control switch. We had Suzuki Quad racers which were 2 stroke - and are a little different.

Did you leave your motorcycle in gear when you turned it off? It sounds like the side stand safety switch is keeping the bike turned off. If my Suzuki is running and I pull in the clutch, with out raising the side stand, and I place the bike in gear with the side stand down, it will immediately shut off. The cycle is set up that way so you will not drive with your stand down and go out of control when you take your first left turn. If your cycle is not in neutral and your side stand is down, that would cause the condition you describe. If that is not the case start by inspecting the side stand safety switch and the clutch safety switch for proper operation.

It seems you have a clutch issue Inspect Clutch plates, clutch Pressure cover, Clutch cable.
It may just be a case of clutch cable slightly too loose

You should have about 3MM play on clutch handle so un-tighten till you can move clutch about 3mm without effort then it should be set about right.

Clutch discs are stuck, put the bike in gear, not running, pull in the clutch and push the bike back and forth to break the clutches loose. Once they break loose start the engine put the bike in gear, hold the front brake, and slip the clutch a little to remove any built up or stuck crud on the plates.

locate the starter motor solenoide & hook up to the positive terminal there! & the earth to the engine or frame ok
Cheers Rob

I think you mean no kick start. Yes there is a way. Push starting it. With you on the bike and another person pushing. A slight downward hill helps also. Just turn on the key and the choke, put the bike in second gear. With the clutch pulled in, start pushing down the hill and when you get some speed, then pop the clutch. The engine should turn over and start.Note : Make sure you are in safe surroundings when attempting this maneuver. Happy Travels.