Help?

So, I’m 16 and I’m 5’2”, I weigh in at 200 lbs (I don’t really look it though, most of it is muscle; I’m a cheerleader) as of today. I love my body but there are some parts that I don’t feel so confident about. It’s my upper arm and like the area around my armpit and my lower stomach. I guess what I’m getting at is how can I start feeling more comfortable with/confident about it?