Hey Bro,
I'll see if I can help. I'm a Corrections Sergeant, and have been on the job for just about sixteen years. Over that time, I turned down a half dozen jobs at Police and Sheriffs departments, when I decided I didn't want to take the cut in pay, benefits or job security from working for the state, vs. County or Municipality.
I would strongly recommend taking a prep course if any are available in your area. There are a few options here in Jersey, and they will help you score better on the written test. Most tests include, writing skills, reading comprehension and vocabulary. There shouldn't be too much Law Enforcement specific topics, simply because you have yet to be trained as a Cop.
For the PT test, start training. natural aptitude sounds nice, but nobody is gonna be impressed with your slender build, when you are sucking wind at the back of the pack on a run, giving up the ghost on sit ups and push ups, and otherwise showing a lack of fitness. If you want the job, START EXERCISING! Different departments test differently. Some follow a basic military PT Test, with running anywhere from a quarter mile to three miles, Push ups and or pull ups, and the ever popular sit ups. The more you can do the better. Normally they are graded by quantity, so the more you can do the better. Form will matter and most that test this way, don't count them if you break form.
Others do physical agility tests, like measured standing jumps, running long jumps, obstacle courses, sit and stretch, and so on. Ultimately, if you want to get on the job and do well in the testing, get out and start exercising...
For the Oral Board, you'll be expected to give brief overview of yourself. Training, schooling, Military, family hobbies, ect. Don't get diarrhea of the mouth, but have something to tell them. Be ready to answer questions about your strengths and weaknesses. Make you weaknesses a back door compliment to yourself, like "I am a very work oriented and anal about doing things correctly, and that can sometimes annoy some folks." Be ready to answer what yuo are bringing to the table. There will be questions that are LE related. Preface the first question by stating that you haven't been trained yet, but will perform within standard and in keeping with their department's SOPs, and then just use common sense. Be ready to maturely explain anything negative they might have been able to dig up on you. Accept full responsibility for your actions, even if you think you were innocent. DO NOT try and shift blame to someone else. You did it, your sorry for it, but have matured since then, and learned from your mistake. You won't repeat it...that type of thing.
Some situations will be a damned if you do and damned if you don't. Be ready for someone to jump all over you, insult, challenge and degrade you. It's a test to see if you are gonna pop a circuit, or maintain your composure. Maintain your discipline at all times. Answer the question as best you can, but don't argue. Always be respectful...DON'T LIE! If you get caught in a lie, you are done. Don't lie about anything...
Lastly, when asked, your friends and family are always supportive of your choices, and are behind you a hundred percent.
I hope this helps...
Respectfully,
Harry