Anyone who already has a network is someone who either isn't looking for a job, or who will already find one without any help or advice for you.
For actual computer nerds, they may not have much of a "network". And so there's no one to ask out for coffee. And for them, your advice just sounds strange.
No, this is exactly who needs this. People who have a network are already doing this on daily/weekly basis without even thinking about it.
Identify someone you'd like to have in your network, and approach them. Start with people you find approachable, someone "in your league", but perhaps a few years ahead of you, and work you way up. If you show a modicum of modesty (so, perhaps your first approach isn't Elon Musk) and be unfailingly polite and respectful, most people are in fact flattered that you want their advice.
After each interaction, evaluate it for yourself, and improve your approach. Rinse and repeat.
For actual computer nerds, they may not have much of a "network". And so there's no one to ask out for coffee. And for them, your advice just sounds strange.