I'm just trying to get some insights from previous applicants about the state of their startup when they applied.

Some questions you could answer :-

1. How long had you been working on the product?

2. How many of you were in the team? How did you meet them?

3. Were you working or had you quit your day job when you applied?

4. Did you have any users that were paying for your service?

5. How was the process? What changes did you make after the interview with the YC partner?

6. Did you get accepted by YC?

7. What were you working on?