Shut off while driving, will not start?

When I got it into a parking lot, I tried starting it and it will not start, it tries to turn over but won’t start. All of the lights work except the lights for park reversed drive all the gear lights they do not work. What could be wrong with it? Why won’t it start? People keep telling me that it could be a relay, is that true? The starter relay has a burnt color on it.