Teen and Weight lost?

Im 15 years old going on 16 soon i wanna lose weight by august i wanna be at least 170 by august... So i wanna try a liquid diet idk what to drink Like is v8 and special K and some apple sauce and pear sauce okay??? Do you think making a youtube channel about it would motivate me?? I have a belly so what are some good effective exercises?? also may i have some tips and advice on losing weight?/