Oct
im mostly concerned about my arms and abs also endurance
Answer:
I would definitely suggest getting a membership to a gym for getting stronger. You should put equal concern for each major muscle group. For endurance you can take a light weight and lift it as many times as you can.
If you mean for running, just start running after school. Run as long as you can. Do this each day except for Sunday and Friday. If you totally HAVE to, don't run on Wednesdays. Make sure you get the same time each day you run. No more no Less. After doing this for two weeks, increase your time by 5 minutes. If you feel like you can run longer, don't. Keep repeating all of this.
To get faster, simply run sprints. If you do the running endurance, you can switch out a couple of the days a week for sprinting. Pushups and ab crunches also help you get faster by allowing you to pump your arms, which helps you move your legs.
here is an excellent youtube channel to check out for tips on getting stronger: http://www.youtube.com/user/scooby1961
Answer:
You are old enough to lift so you should probably try that and to get faster ladders. Ladders will also help with foot work and the superior the foot work the faster you can run.