I think the effectiveness of a good cold email is underestimated - a short, thoughtful email will often be well received by interesting, smart and very senior people that you would not ordinarily have access to as a young professional. I also think a strong cold email is better than a lukewarm introduction.

I have stolen / adapted these tips from https://sriramk.com/coldemail

Keep it short

No more than a few paragraphs. Your reader does not have time.

Explain who you are

Why are you worth paying attention to?

(a) Demonstrate credibility through past roles / institutions.

(b) Alternatively, link to a website, portfolio or body of work until you can do (a).

Explain why you sought them out

You don't always have to do this but sometimes you can point to an article they wrote or some shared connection - maybe you are alumni of the same institution or have similar backgrounds.

Offer a value prop for the receiver

Whats in it for them? Offer ideas for their company or a thoughtful response to something they wrote or are passionate about.

Have a specific ask

"Career advice" may well be too broad.