My(M29) ex(F30) wants to catch up. What should I expect and what are the possible do's and don'ts?

Hello people. So my ex from college days is back in town and has reached out to me to catch up. It was a complicated situation back then with messed up feelings for each other, though we were never officially in a relationship. We parted ways 5 years back because it wouldn't have worked since she wanted a different lifestyle out of the city. We got back in touch over social media some 2 years back since she was away. Now that she is back in town she wants to catch up. I said yes. But am confused what should I expect and what could be the do's and don'ts. Please advice me.