How early should I arrive to find seating for the 9 am service?

15 min early is a comfortable time to arrive to get seating and say hi to a few folks before it starts.

20 minutes is a good time.

I remember them having shuttles to the building as well.

You might want to arrive 25 to 30 minutes early to avoid the parking lot congestion

You can find a single seat anytime but if you need more than one seat side by side, you should get there 15-20 minutes before the worship starts. But to find a good parking spot close by, you need to be earlier.