Well, that's kind of a vague question, but I'll do my best to answer.
If you turn the key and hear nothing, I guarantee you that something is wrong with the wiring to or the wiring of the starter or starter solenoid. Check the wires from the firewall leading from the ignition to the starter. Make sure the wires aren't frayed or anything. Then look at the starter, if it is obviously a little damaged, it is more than likely that. Then check the wires leading from the starter to your engine; again, if anything there is frayed you're probably just having a short.
But if you got into an accident, I definitely recommend having a professional check it out. Driving around with a faulty radiator is also not a good idea. If you don't have the money to tow it to a shop and have it looked at and nothing above works, take a bus...
