“You don’t sound confident”

The issue here is that your close was premature. You didn't build any investment from the girl and their was pretty much no vibing. Also, she was mildly trolling you throughout the conversation, it was important to kind of "give her some shit back"

For your follow up you can say "You don't sound confident"

Slow your role. You don’t have buy in. She isn’t yet invested. You did the right steps, way too fast. You need some real back and forth- where you from originally? How’s your day going? Etc.