I would try to establish a friendship with them rather than trying to transactionally extract some useful knowledge.
Consider what you can offer them rather than what they can offer you.
“Would you let me buy you coffee or lunch some time?”
Find out what they are interested in outside of their career, or if they share any passions of yours.
Ask them what they’ve been reading, watching, or listening to lately. Then you could engage with that media yourself and have something interesting to talk to them about.
I suggest you read the book How to Win Friends and Influence People. Never Eat Alone is another book I’ve heard good things about on this subject.