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

I sent 18 messages on a professional network and got two replies. There are 18 people counting on me, so I am trying to be careful. I want advice, not a job directly. What did you ask?

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.