how do i find out if my starter has gone bad

Did you actually test the battery? It can have enough juice to operate the lights (3-5 amps) but not the starter (100+ amps). Disconnect the cables and clean the connections inside and out and try it again. A process of elimination is how to see what shape your starter is in - test the battery: clean and tighten all the connections; check fuses, check for power to the starter. The only other thing I can think of is a seized (frozen) motor. Usually, the clicking sound means that there aren't enough amps to engage the heavy load of the starter so the solenoid "clicks".

pull it and bench test over at NAPA (or equiv.) they will do it for free, then we will know that it's your battery is old (note the pushoff labels on the top of the battery indicating the month/yr of it's first charge) if older than five needs to be replaced otherwise you'll and up having to buy an alternator too~ a new Interate will be about $125 and worth every penny~