After you choose who you will cosplay as, you should check a costume store like Party City to look for wigs, dresses, fortnite halloween costumes etc. (or just check online). Then there are the classics, like this Civil War costume and this women’s Captain America suit. A costume based off Harry Potter would be the perfect wizard costume. Try typing ‘Alice Pandora hearts cosplay costume’ or ‘white cotton gloves’ into a search engine, guardians of the galaxy costume and you should find some.