Kissing is tricky. It can kinda be like Goldilocks: a little too hot, or a little too cold. They key is to make it just right. But how? It's easy to be a little too intense, or not intense enough.
First, start small. And communicating about what's working really does, well, work! Another piece of advice is to mirror your partner. If they kiss softly, you kiss softly. After all, lips do have 100x more nerve endings than fingertips.
And remember, there's always other real estate. A shoulder, the neck are good places to visit.