Take the last 3 digits from your post. that is what pokemon you are. if the number exceeds the amount of pokemon, you just use the 2 other digits (i.e. 753 is just 53). if your first number is a 0, then you are a person. if the second number is odd, you are a trainer. if even, it's apart of team rocket.

after you find out what you are, the next post will determine where you are. simply put, whatever number you get is your current location through routes (get 12, start on route 12). then you can just move to whatever place is near you. if you find another person is also on that area, you will meet them and fight them.

good luck on your pokemon adventure!