Gaining muscle for metabolism?

Question

what is the best way for a 14 yr old 5 ft girl to gain muscle in order to increase metabolism?

Answer 1

At home, do push ups ( 3 sets of 8, build up to 30).  Squats ( 3 sets of 10). Abs (long arm crunches-these work way better than regular crunches).

Answer 2

Lift weights.

Run sprints.

Swim (sprint style not endurance)