I need some ideas for cosplay!!

That depends on your look. If you don't wear a peruke and a bought costume then you should dress like somebody with the same hair color as you. I recommend Nico Robin from film Z for black hair. Nami in her dress camisa water 7 outfit for red hair and any outfit from Lucy Heartfilia for blonde hair. Those are easy to make even without having to buy a cosplay.

Anyone with your hair color, or if you have a lighter hair color, you can dye it to the color of any animê character with colored hair (Examples: Fairytail; Natsu, Jellal, or Juvia. Ouran High School Host Club; One of the twin's hair when they had their fake fight) You could get a wig too, if you want. For the body , it doesn't really matter if you are skinny or if you have big muscles. That's just how animê characters are made. Boys are muscular, girls are skinny, but that doesn't matter. For skin tone, you can wear face paint, or wear clothes the color of the skin of the character. I hope this helps!