Tesla
Tess, if you really love this boy and you think he's worthy of being your first, age doesn't really matter. You're not 15 honey. You know your own mind.
What Shawn doesn't know won't hurt him. You have to think of him like a parent. You listen to what they ask, obey the rules as best you can, but don't tell them all the details that they don't need to know. There are some things in a girl's life that deserve to be private. I doubt he'd want all the details of his romantic life broadcast over the internet either.
Someone has to be the first, Tesla. The only thing you can do is make sure that you both care about each other enough to respect that sex is a big step, and that it's special. Especially the first time.
And only you will really know if you're ready. I'll always be here if you want to talk, sweetie.