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

A friend suggested informational chats and I do not know how to ask. This is my first time dealing with any of this. Some people reply with short answers. 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.