I drive to all my appts. I usually try to be early. I hate to rush in straight from a stressful drive. For that reason, I budget an extra hour travel time in case of traffic, and an extra half hour for me to decompress before the meeting. That's something I've learned...but calamities have happened...flat tire, forgetting something essential, horrible traffic jam, getting lost, injury.
If he's stressed (or if I am) I find a light drink or refreshment helps calm the jitters. If I'm hosting, I usually have something on hand.
I guess a warm-up round will also help shake those jitters off

It will definitely change the mood quickly

If he's super-stressed, that's probably where I'd head.
If I'm really nervous - lateness, first meeting, got lost, etc...the best thing a guy can do for me, is just to chat, offer a drink of water or something else, and let me breathe/relax for a few minutes while I calm my mind, and turn my focus back on him