Weight gain/weight loss tips?

So I’ve just signed up for a Pilates class on my phone because I want to slim down. I’m fairly blocky, don’t have the curves I want, and I’m considered overweight. Would I be doing myself a disservice by dieting and exercising? I ask because people will say that you need to eat eat eat but weight gain actually kinda triggers my dysphoria a bit more tbh because I hold weight in places that make me look buff. And honestly I just want to be smaller, I’d love a more feminine looking body, but ultimately I’m a muscular person and I want to be just skinny