Why do you need to tell a girl this information? So maybe the first time you kiss the girl will think you're a bad kisser (or who knows, maybe not). Does it matter? It's not like it's a mechanically hard thing to do.
Here's what I'd recommend: when you reach a point when you're about to make out with a girl, just do it. If, afterwards, the girl comments that something was weird about it, you can sheepishly admit to her that it was your first kiss. If anything, I think that'd just make you more endearing anyway.