Perhaps the best-know Sun alum is Kurt Vonnegut. He put his reporting skills to good use as a POW during the bombing of Dresden. Which eventually resulted in “Slaughterhouse Five”.
Cornell also offers other opportunities/venues besides the Sun to get one’s written work in front of the public. Which is what you want to do if you want to work in journalism, I think.
Doesn’t mean W&M does not have similar opportunities, I’ve no idea.
If I were you I wouldn’t bank on any “alumni network” helping you very much. What will best help you is the experiences you can accrue. Your actual demonstrated capabilities.