What will these excercises do ?

I'm 13 and I'm 105-110 lbs. I eat ALOT of food and junk (im not gunna lie) so I need to get my exercise everyday. So at night before I go to bed I usually do 40 situps straight and 20 to the left and 20 to the right. Then I do 40 squats. And I stretch an stuff. But I read that this builds muscle but I need to loose fat. Not my weight or anything , just make me slimmer. I get the fat at the bottom of my stomach and on my thighs. :p What are some good exercises that I can do everynight that aren't too hard that can help me with this ? And explain how to do them please. Thankyou. <3