Help with weight

I'm 5'8 156 pounds and want to lose weight. I want to be around 135 or 140. I'm not fat (even though I feel it) just tall and have a little bit of fat on me because I got into a car accident a few months ago and haven't been able to do anything active. Now that summer is here I want to lose some weight and get a flat stomach and I was wondering if any of you ladies could help me out on some things that help you lose weight/get a flat stomach!? Thanks😊