Cold messages to people in my field, do they work?

A friend suggested informational chats and I do not know how to ask. There are 6 people counting on me, so I am trying to be careful. I want advice, not a job directly. How do you phrase the request?

Keep everything in writing and save the confirmation numbers. It saved me later.

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