Breeding is a VERY involved process and while I admire that you are taking the time to recognize the importance of titles, health testing, and finding good dogs. Without having a nicer way of putting this, its really far much deeper than that. Its a fantastic place to start, but you shouldn't start just because you have a starting point.
You should learn about dog body language, why would you benefit from this? Because as you are raising your own dogs, purchasing dogs, viewing potential dogs for breeding etc. its important to recognize if a dog is visually uncomfortable. Then comes into play WHY that dog is visually uncomfortable. Is the trainer/handler extremely hard on the dog and the dog cannot handle it? Does the dog have handler sensitivity but overall hardness to its environment? Does the dog hate loud noises? etc.
You certainly don't want to breed a dog with an unstable temperament or too much aggression or too much fear. And you need to learn to recognize what kind of fear you are dealing with. What is genetics and what is nurture?
Then that aside, you need to learn what goes into training a dog, the different training styles etc. Because if you intend on titling a dog, you need to find the working ability in an individual dog that suits your needs the best. Not every dog works the same, in fact every last one of them is different. Similar but different.
What are your goals for breeding? To get a dog out of the litter to keep for yourself and have fun titling until the next litter? To produce a bunch of pets to sell? to produce a bunch of show dogs and potentially keep one to campaign yourself?
Understand the standard of this breed, and the standards of other breeds to compare. Why does this breed require the things it says in the standard? Where does the line get drawn at extremes in both drives, and structure. What does this look like in person when you get your hands on the dog? How do you recognize conformation in movement, and then in a stack? What sort of things can you hide in the stack with specific photographs and how do you find these things out to make sure you don't pick out the bad dogs.
Learn how to tell the difference between drives in dogs. What is prey drive? What does it look like? What is defense drive? what does it look like? etc. This will give you more insight into how a dog was trained.
How do you find the right dogs and evaluate them for your breeding program? Will you title all of your own dogs? You should probably gain an understanding of the sport you intend to title your dogs in before you consider using the first dog you trained as a breeding prospect.
If you don't understand everything that goes into training the dog and why you had to do it this or that way for this specific dog, then you won't have the know-how to match that dog correctly with another to improve upon their qualities.
You say you want dogs that can be used with police departments. Please keep in mind that is a vastly different dog than an amazing pet quality dog. Most people consider a pet quality dog to be one who lays on the floor quietly by the fire staring up at them with longing eyes all day long with little to no exercise.
There are many dogs who can work, but each one works for different reasons, different lines of German Shepherds require different types of work to bring them out in the best way. All of which on the surface looks like the same thing. When you dig deeper each dog has a different fundamental reason for doing the work they are doing.
This is just breaking the surface. I just wanted to give you a heads up and say good for you for going for what you believe in and want. But think less about the overall picture of trying to get a litter of puppies as soon as possible. Slow down, enjoy the ride, learn as much as you can, from as many people as you can (because no matter what you will ALWAYS deal with biases from every party), and when you get there, the blood, sweat and tears will be that much more worthwhile and the dogs you produce will be completely worth it. You won't regret a minute of it. You are 17, take your time, there really is no rush.
"For the animal shall not be measured by man. In a world older and more complete than ours they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear."