To reach a certain level and to avoid injuries, you will need proper equipment.
You will find a brief selection of good equipment on this page. Everything, except for the shoes, are suitable for all audiences.
A good sports watch and a good HRM
are very important to properly measure your workouts.
While a backpack and a waterpack is not for everybody, in my case it's a pretty good addition, especially for long distance training.
To properly select shoes for yourself, I highly recommend going to a decent running shoe retailer. After you made your offline selection, you still can buy newer ones online. Good shoes will protect you of possible injuries.