Host a yard sale to get rid of things you don’t want anymore. Clean out your room and gather up all of the toys, decor, and clothes that you no longer use or want. Display your items on a folding table in your yard or driveway with your parents' permission. Put prices on each piece with a sticker label based on what you think it’s worth and the original price of the item.
Amazon makes it fairly easy to list and sell old books, games and devices on its marketplace. You can make more than just a few bucks If you have pricey textbooks from college. Be sure the books are in good condition. You'll get negative reviews if you attempt to sell books that are falling apart or games that are scratched up. Remember, be upfront about any defects, no matter how small they might be and no matter how few people might readily notice it.