Press credential policies vary from state to state. Here's the link to credentials for NJ, where I live: http://www.njpa.org/credentials/index.html, and the link for NY is http://www.nyc.gov ...entials.shtml#eligibility. So yes, theoretically, you could create your own media outlet. But you would need to show some history of publishing news stories. But, generally, you don't need credentials unless the police have barricaded an area you want to access, or the area is generally not open to public pedestrian traffic (e.g., private property or highways). But even if you don't qualify for state press credentials there's generally no law forbidding you from printing-out and wearing a generic "WORKING PRESS" ID to identify you as a non-participant. Won't help you with the police for access but might help keep you safe in some situations.
My experience (which is now a few decades old) is that everyone except the police and looters are happy to have press coverage. The police will tolerate you if you (a) have credentials and/or (b) stay out of their way and don't attempt to pass any barricades. Protesters only protest to get attention. Victims want their stories told. Even rioters and looters think it's cool to be on camera (as long as they're smart enough to cover their faces). There is some risk to carrying expensive gear in high-crime areas, and I know of one case where a photog was mugged for his gear. There's an informal but mostly universal policy that you don't mess with the press, if for no other reason other than they can make your cause look bad if you do. Still, it is possible to get caught up in a crowd reaction so always be aware of your environment (situational awareness) and move early.
We mostly relied on press releases or PR contact notification, and listened to police scanners during our downtime. You used to need a permit from the NJ State Police to use a police scanner in a car, but I believe that's been changed to just make it illegal to use one in commission of a crime or to interfere with police or emergency services (which might be broadly interpreted to cover the press if they were determined to be an interference - interpretation is up to the judge). Get the city editor/desk phone number for your local and regional newspapers and TV news organizations and put them on speed dial; this is who you'll typically contact to sell your photos. And once you establish a good relationship you can call in to see if anything's happening that needs coverage, and eventually they might call you.
Wide establishing shots are expected. But then shots of any violence, vandalism or looting are easy sells. Yes, if it bleeds it really does lead. Confrontations between protesters and between protesters and police. But also tight shots showing emotion. Your shot needs to tell the story. Remember that space is premium and a photo should interest a reader in following the story through the page jump to where the rest of the story (and the ads) are printed, or the viewer through the teaser and commercials to the main story.
Today you can and should shoot both stills and short video clips. Clips should be around 40-45 seconds long with the main story told in 28 seconds or less; the extra footage before and after is sometimes needed for smooth transitions.
Gear should be rugged because it will get bounced around, and have a good strap because you'll be bounced around too in some cases. And weather/dust sealed. 8-12mpix is sufficient for most media outlets, though higher resolution gives you more cropping options in post (but minimal post time should be spent -- first person to file is generally the one who gets published -- this is the main reason pj's are using iPhones now). Reasonably high FPS, fast autofocus and good high-ISO performance are important. I would look at the 1D* or 5D*. Two bodies, a 24-70 and a 135 or 70-200, (or 24, 50 and 135 if you prefer to use primes), plus a pair of flashes (with flash brackets and cables) should cover you in terms of gear. If you prefer crop bodies, a 7D* or maybe an 80D would do the trick, with a 17-55 and an 85 or the new Sigma 50-100/1.8. And always carry a smartphone to shoot and upload photos in real-time for breaking news events.