Cosplay is for children of all ages from 8 to 80. If you want to dress up like your favorite character, then do it. Don’t worry about what others might think. Consider what you feel about it. You will find others your age who love to wear cosplay costumes as well.
If you have talent for making clothes and accessories, then go ahead and create with your own hands. Be resourceful with materials so that you can turn your imagination into reality with what’s available and affordable. If you don’t have any experience with dressmaking, then you could buy the costumes from online stores.
Several websites specialize in cosplay outfits. You might have already seen some of their items in various conventions and other events across the world. They have pieces for popular characters and generic items for different periods or genres.