Good excercises to lose weight b4 school??

If I were you, I'd use at least two of your exercise equipments at least 3 times a week. And watch your calories/portion control (1200-1500 cal/day depending on your size). If you are strict about your diet and exercise routine, you could lose about 2 pounds/week...which is 12 lbs in your alloted time. You didn't say how old, tall, or overweight you were, but 12-15 lbs on a shorter person looks like more than it would on a taller person.