How do I lose weight? Get rid of my stretch marks?!

How do I lose weight? Get rid of my stretch marks?

I am 13 years old, 110 lbs, and 5"7.5. I want to lose weight in my thighs. I have very small shoulders and upper half, and usually wear a size 2, but in the bottom, I feel I need to get rid of my butt and hips. I need to, and hopefully that will get rid of my stretch marks, but if if doesnt i dont know what to do!!

Any suggestions!

THANKS

start out gentely:
first week:
monday: run up-hill or on a tredmill for 5 min sets. in between the running walk at atleast 2.5 mph. while running go at a comfortable speed for you. after you run be sure to stretch
tuesday: optional, swim 1/2 a mile. try to kick as much as possible.
Wednesday: repeat monday, but change it to 8 min. sets.
also throw in 2 sets of 20 squats.
thursday. 2 sets of 20 squats. try to do a fast pace walk for 40 min.
friday. swim 1/2 a mile kicking. also try to do ( if the pool is shallow enough ) underwate sprints (3 laps)
saturday. DAY OFF! take some measurements.
best of luck. also fell free to alter the schedule.
this is just and example and because u r young, only exersize 3 or 4 times durring the week. neway, for the stretch marks put on some cocoa butter.
good luck