So, you want to start running competitively but don't know where to start? And on top of that, you can't pay for a trainer to tell you what to do? I've been in this predicament before, and I suggest going to runners.
Preferably, I would suggest going to close family and friends in this situation, but they might be runners. So, I suggest joining a runner's club in your city. Many of the runners in those train competitively in their spare time, so asking them questions about their routines is key. As additional advice, bike riding also helps tremendously with running.
“Many of the runners in clubs train competitively as well”