How do I ask for an informational chat? - 14 months and counting

I sent 13 messages on a professional network and got two replies. I am in Birmingham, in case local advice matters. I want advice, not a job directly. How do you phrase the request?

Follow up with a thank-you and a short update. One of my chats led to a referral a month later.

I asked what they wish they had known at my stage. People enjoy answering that.