Before picking an event or starting a training program, you need to decide on your goals. Your goals are YOUR goals. While one person might be trying to brake 25 minutes in a 5k, another might be attempting to finish a 100 mile race within the time cutoff or run their first marathon or even their first 5k. If you are interested in beginning a training program, the first step will be deciding on the short term and long term goals of which there might be several. Worrying about what others are doing or giving in to social pressures is not the answer- plan YOUR goals!
Do you want to stop getting injured, but also want to improve your speed? Both goals need to be tackled, but first, getting to the root of the injuries is key. Is it your running form? There are plenty of techniques and drills to improve upon your form and these need to be incorporated immediately- increasing the amount of running will just worsen the injuries in this case- probably not improve speed, or if it does improve speed it will still worsen the injuries- vicious cycle! Getting faster is great, but sacrificing health to get there is hardly worth it in my opinion. There should be a balance.
Training the mind is just as important as the body. The human body is truly amazing and can do unbelievable things with the right mindset. This is an important piece in the training puzzle and should never be ignored.