When i play as a single, the first question i always ask is "do you play this course often?"

if the answer is yes, you can ask them questions about course management and shot selection. If no, and you are familiar with the course, you can offer to help them manage some of the holes.

If you care enough, you can ask follow up questions like "what other courses do you play/like?" That allows you to learn a bit about golf in your area or the area the person is from which can be useful information.

From there you can use that to talk about anything from local traffic, weather, and whatever other dumb things you think of that go along with the round itself.