Tried to start my van it turned over once and now nothing ,all lights work but no srart

Hello, If everything is coming on like normal, but the starter will not engage, have someone turn the key to 'start' while you remove the starter relay. If the relay clicks in your hand as it comes out, you know it is good, and that the ignition switch is not the issue either. If it does not click when turning to start, turning from start to 'ON', or removing while the key is turned to start, check for power at the relay when the key is turned to start. Your main job here is to narrow it down to the ignition switch, starter relay, wiring, or the starter. If the security light is on, you have an anti-theft issue, which will require diagnosis to find the cause.