Please help me in finding the reasons in which sleep is good for you? Also how do i get my stomach flat?

I am looking for healthy habits to get into. Also I am looking for things I can do that will get my stomach flat and not have a gut poking out at the bottom of my stomach. It is really strange! My stomach is flat at the top but the bottom isn’t! Why is this? Also I am wanting to know why sleep is important, and what I can do to make sure I get a good nights sleep. THANKS!

-Ryan