Cold messages to people in my field, do they work? after 3 years as a software tester

I sent 3 messages on a professional network and got two replies. I have been trying to stay organised about it. I want advice, not a job directly. Did any turn into leads?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

Do not apologise for asking. Most people remember someone who helped them.