What's a good fat loss workout routine? And get a good body in about 4 months?

I want to lose fat
What's an exercise routine that I can do to lose most of it?
I started drinking about 3Litres of water a day about a week ago
What can I eat?
And in the exercise routine, how heavy of weights if there's weight lifting , specific things

PLEASE HELP
I'm a guy
I'm 16 years old
I weight about 150 pounds
I'm 5'11" or 6 ft tall
Most of my fat is on my front part of my body like my stomach and chest