You’ve just finished the first book ever for Ruby for kids. Now, move to Silicon Valley and ask your parents for some seed funding. Soon you will have raised a Series A round and have a large equity stake in your very own tech startup! In no time, you will be able to give your parents an allowance.
In all seriousness, one of the beauties of programming is that there is always more to learn. You have crossed one of the most difficult hurdles by simply finishing this book, but this is only the tip of the ice berg. Check out the many resources online to learn more about Ruby and other great languages, go through some tutorials, start building things and hone your craft.