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

A friend suggested informational chats and I do not know how to ask. I have read a lot of threads here and could not find my exact situation. I worry about bothering people. How do you phrase the request?

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

Thanks for writing this out. I went through something close to it 6 months ago, and it got easier once I kept a simple log of every call and form.