Any tips on losing weight?

I've been overweight for all I can remember but I think I'm ready to actually do something about my weight. I am about 30-40 pounds overweight. I can't change my diet much because I'm still young so I live with my parents and my mom doesn't have much time to make food in the first place so I don't wanna put more work on her. I also don't want anyone to know about me trying to lose weight. I dunno why I guess I'm still self conscious and if i told someone like my mom she would talk about it and everything and all my family would know and it would be annoying and just I don't wanna get into that mess. I don't have many options for exercise because I can't leave the house and let my parents know what I'm doing and I don't want anyone to see. It probably sounds impossible to do anything with my conditions but I'll take any help.