You are doing well in life's small adventures mate! There is unlikely to be a law against impersonating a journalist/professional photographer but you should try and get some credentials .... Not necessarily a Union, it could be a Professional Association and you might get in by offering your services to be listed as a self-employed local representative for a nearby newspaper or TV station. Or as I did, many moons ago, start and print and edit your own local journal and get the credentials started that way. Offer pictures to local news services and try and get some high res. video as well, inexpensive and very portable these days. Local interest pictures you offer for free but wanting attribution at first may be the way to go, gets you some status and a portfolio, then you can move up.

Don't forget, all though you gave up on Computer technology as a career, these days you can justifiably start, run and publish a web magazine and gain credentials that way. Use a modern internet connected phone or wireless netbook all set up for quick uploads.

Get up to date with the laws of privacy as apply in your country (spend a bottle of whisky on a session with an experienced journo, never met one yet who wouldn't enjoy that, male and female). Think about insurance too. Third party as well as your own. Good luck, follow the dream - many photo-journalists started out on a motorbike I am sure!