Girls, how do i feel good about myself beside, slutty, popular, easy girls who get whoever they want?

when im beside them i feel really ugly, and fat. because guys mostly pay attention to them. im not fat or ugly though. sometimes i want to just wear really slutty clothes, and act like a tramp because it would be so much easier, but id rather just feel good about myself when im being myself. im 14 in grade 9. what can i do to feel better beside them?