I'm about 15, and I try to brisk walk about 5 miles at 3mph. 6 times a week, is this a good workout?

well your weight goal is good you want to lose weight slowely not fast and two pounds is good walk the speed you can handle then add to it this is probably the best way to reach your goals try adding to it as you go like you said you would add to it watch your carbs your calories intake healthy eating will also help fiber is also good for the body they say we need excersise 3-4 times a week cut sugar intake down this will also be healthy read labels on things you eat and drink