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

I want to talk to people in a new field but I hate cold messages. Any experience at all would help. I worry about bothering people. How do you phrase the request?

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.

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