How to become a photographer for the Media/Press?

I wanted to know how do I become a photographer, and get a Press ID for agencies like, AFP, Associated Press, Getty Images, etc. I like taking photographs of happenings like protests, disasters, and the like. But how do I do so? I'm based in the Philippines.

You build up a portfolio that shows that you can do consistent photojournalism and present that portfolio to those associations. If they hire you based on your portfolio, then you get a press pass and get assignments to go shoot in your area.
Your portfolio should consist of 15 - 20 of your best images. Having a photo essay shows that you can do long-term projects.
Just realize that the photojournalism community has been shrinking for about a decade. The industry is the midst of switch from hiring pros to paying next to nothing for someone's iPhone photo of an event. So the competition is fierce and the payoff is low. Even if you manage to get the cover shot for a major magazine or the front page of a newspaper, you just might get $125 for the use of the image.
If you're still eager to becoming a PJ, and you already have a year or two of learning photography, then expect to spend up to two additional years of constant shooting every day before getting enough good images for a portfolio.

I started out by working as a staffer at the universities newspaper.

With all may tearsheets, I was able to find work with a local newspaper

Sadly, as mentioned above, there are fewer and fewer positions for photojournalists.