Be in good shape. Train for long distance running. Criminals only train, for short distances. Maintain good credit. Avoid alcohol and drugs. Apply to as many departments as you can! Maintain eye contact in your interview. Everyone likes an honest candidate. You cannot be trigger shy. If you can’t pull the trigger, you can’t be a police officer. Doesn’t mean you have to be trigger happy either. They will spot that real quick. For each department that you apply, learn the history of the city and the department, if you can.
Listen to the scanner. That can be inspiring and give you a good idea, of some of the things to expect. (http://broadcastify.com /) Look for the department that you are most interested in.
Go to a college or junior college private police academy, get a four year degree in criminal justice, or the military. One of the three usually seems to suffice.
Riding with the police always helps. That way your foot is already in the door. You may just get handed an application at the end of the shift. When I was 21, I rode with the supervisor, of the Baltimore City Fire Dept. Before the shift ended, I was offered a job as a paramedic. I never applied, or even inquired. I just listened to all the words that came out of his mouth. So if you ride with the police, just sit back and listen. Best wishes, and message me, if you need to. David.