My 1993 Dodge Caravan won't start. There's a clicking sound under the hood when I turn the key. I was told to reset the map sensor. Although, I don't know how. I put in a new starter yeste

Do not go back to any " mechanic" who told you to re-set the map sensor. Those are some baaad mechanics, giving you a schuck job. That is outrageous . If the clicking is coming from the relay and fuse center by the battery, you probably need a new $10 starter relay. If the clicking is coming from the starter solenoid on the new starter you put on, then it's not a bad part, but likely a loose connection at the battery, or at the starter where the big cable wire attaches. Are your battery cable connections corrosion-free and clean and tight? Did you happen to remove a ground wire and forgot to re-attach it? Check your battery ground, the negative cable where it attaches to the frame of the car, or to the engine. That should be clean and tight also. If the starter solenoid is clicking, it means that the starter is getting a signal from your ignition switch to turn the starter motor on, but the starter motor is not getting full battery power from the battery to start turning and thus cranking the engine. The starter motor gets its full battery power from the positive positive cable. One end is on the battery, and the other end is on the starter. If your battery is still charged up enough to start the car, all connections are tight, you have a new starter, and the solenoid just clicks, it may be a bad battery cable.
I will stop here, and wait for your response . Hope you find it, just keep looking. There is no such thing as re-set the map sensor, period.