For running, 5.5~6.0km/h is enough. Run slowly and walk fast, but remember to run for more than half an hour at a time and fix it at least twice a week. The most important thing to lose weight is not speed, but time. In half an hour, no matter how fast you run, you won't lose weight.

13 years old, the most important thing is to control diet.

I remember when I was 13 years old, I was very fat, certainly not as heavy as you, but I couldn't go to the gym from 10 to 18 years old.

I think, at your age, you should play basketball more, just eat less for dinner, and you will naturally lose weight gradually.