If your bike is a VT500 then it does not have a fuel pump.
It has a vacuum operated petcock with a gravity feed system.
Here is the trouble shooting list from the service manual for "Bike won't start".
1. No fuel (or bad fuel) in tank
2. No fuel to carburetor
3. Engine flooded with fuel
4. No spark at plug--faulty ignition system
5. Air cleaner clogged
6. Intake air leak
7. Improper choke operation
8. Improper throttle operation
9. Faulty purge control valve (California models)
You need to look into each one of these areas and find out what is wrong.
When you go to start make sure that you have
a fully charged battery
that you are using fresh gas
the petcock is in the ON position
the Choke is in the full ON position with NO throttle
that the kill switch is set to RUN
Hope this helps