I imagine what a woman experiences is much the same as what a girl might experience, with less giggling, so I'm game.
First kisses are fun, because you're sort of exploring each other. It's all new and fascinating, to discover the way the other person kisses. Do they thrust with their tongue, or is it a gentle sort of exploration? That sort of thing...
As you kiss, you can feel a lovely tingling working its way through you. Nipples become more sensitive, and begin to peak a little. There's a warm feeling pooling low in your belly, and you might begin to experience a little wetness as your arousal grows. I'll assume hands are busy exploring as well, and those touches are going to intensify what you're feeling. Gentle teasing or rubbing of the nipples, hands tracing the curves of hips and buttocks, or wrapping around a slender waist...
I don't imagine the gender of your partner is going to affect the way you feel as you grow aroused, but given that I have no interest in or desire to sleep with another woman, I can't help you there. But it's your story, and your fantasy, so I say go with it.