I have lost all water pressure. All faucets and others water outlets down to a trickle. I am on a well, tank has no pressure indicator, separate pressure indicator reading zero. Any idea

1. Check the breaker. Is it on?
2. If so, then take the little grey cover off the pressure switch. There are two pairs of contact points. Are they touching?
3. Look on the side of the switch. Does it have a little lever? If so, use that to reset the switch.
4. If the points are touching and the breaker is on, then your pump should be running. If it is above ground, then that is easy to decide. If it's in the well, then try placing your hand on the well pipe. If the pump is running, then you can generally feel a vibration (almost like a humming) in the pipe.

Let's get that far and see what you have.