Some good advice on here.
I have many years' experience on newspapers and magazines (I was also a teacher of MFL in the middle!) and have been working in comms roles for the last few years.
Happy to answer any specific questions your son may have.
To add to what's said here; there are degrees in journalism, and you will often find people observing that many journalists working today don't have a degree in journalism, but rather in some other subject. This is often because journalism degrees are a relatively recent phenomenon. That's not to say you should or shouldn't do one. Some are very good (Sheffield, Derby) and I know a number of young people working in journalism who did a journalism degree.
OTOH there is no doubt that it will limit you, while a degree in history or English or biology may open more doors. If you are certain you want to be a journalist, then a specialised degree will teach you lots of useful skills and also offer you good contacts (most courses IME are taught by former journos who know a former colleague or two). If you are less certain, maybe look at a degree in a subject you enjoy and consider a post-graduate course in journalism.
But the most important thing to be doing and NOW is to write. You say he did some writing for the college paper - great ! What else has he done? Does he write a blog? theatre reviews? music or comedy reviews? previews of sporting fixtures? It has never been easier to get your work published - any actual printed newspaper is so short of staff that it will probably welcome your contribution - or you could get it online easily enough. As an example, I love athletics; if I were to write a profile of the summer season for the rising stars of a local athletic club, and submit it, with decent quality images, to my pet sports journalist on the local paper, I know for sure he would publish it. Has he done that sort of thing - because if I were looking to employ a journalist I would expect that as an absolute minimum.
To finish (sorry for essay! <gets out blue pencil>) I would echo those who say journalism is not well paid (no need when so many are so keen to do it) and it is competitive. If you want to work on the nationals, you have to be prepared to work long hours, do shifts no one else will take, be freelance with no certainty of work, and live in London (or be able to get there). If it is your passion then you need to show that. Best of luck to him and as I say, AMA.