Age is as much a factor as anything else when it comes to swinging. You will find that many people will say that they won't swing with a couple as young as you for a variety of reasons including the feeling that you
1. aren't mature enough
2. aren't established in your relationship enough.
Here are a few links for you to previous threads on this topic that you might want to read through:
Does Age Determine Your Maturity To Swing? Young Swingers Age Young Couples
As you can tell from reading these, you aren't the first young couple to be interested in swinging or the first to have your questions. Hopefully, these topics will help you answer some of those questions.