Starting 8 weeks before they reach their goal they need to begin to stretch, eat healthy, and start jogging. Once they get a few weeks into their training they would pick up the pace by adding either longer strides, longer distance, or faster times to add more difficulty to training. They should always be hydrated and eat considerng those two subjects will give them the most energy.
I would buy a beginners soccer ball. Especially playing with friends. I would get a normal soccer ball that would be made of synthetic leather. Then, the more I play, I would get a more professional soccer ball.