idk what to do to lose weight

I (19 F) have always been a bit chubbier, but i’m so tired of feeling insecure and not being able to wear what i want confidently. I’ve tried to follow everything but it just doesn’t seem to work, then i learned there’s a whole different set of rules for people with pcos?? I don’t know where to start and i feel so lost. I feel like i’ll never lose it and all these things to keep up with are so complicated. I’m sorry for complaining but i just need help i’m sorry. I have no idea what insulin resistance is or what im supposed to do about it or how it effects weight loss, i don’t know what to do to lose weight. I’ve tried walking and calorie deficit so much but nothing works. I’m sorry if im being annoying but i just don’t know what to do or where to start , im just tired of being insecure. Someone please help if you could.