Losing weight

I need tips and advice on losing weight. I need to lose 40lbs and I don't know where to start. Please help. 😞😞 I use to be so in shape before I had kids now I look like a fat Apple. I know I'll never look thin as I was before but I really need to lose weight because I'll feel a lot better. I gained weight from my Depo shot back in October 2016 and got off of it May 2017 and gained so much weight when I was on it. I hate how I look so much I don't feel comfortable undressing in front of my SO anymore or buying myself anything nice to wear 😞