How do I ask for an informational chat? - 19 weeks in

I want to talk to people in a new field but I hate cold messages. There are 7 people counting on me, so I am trying to be careful. Some people reply with short answers.

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

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