Indeed, you don't have to win any fights in prison you just have to be willing to fight. This is usually instigated by The Punk Test, where somebody will try to incrementally take advantage of you, by either saying something and seeing if you let it slide, then later bumping into you, finally taking your stuff, ect. If you don't fight typically you will be kicked out of that unit and forced to go to another, where your reputation will of course travel with you and they will make your life hell there as well.

Article could have said something about how to avoid needless fights (prob in the book I assume). For example, being in the yard and some guy is looking to start a fight. "What are you looking at?" of course, the wrong answer is "Nothing" as the reply will be "So I'm nothing goof?". The right answer is "Sun in my eyes, no disrespect". You both walk away as respect is maintained and dude trying to bait you into a fight figures out you aren't an easy mark and goes to harass somebody else.

There is also a saying "Do your own time not somebody elses". This means somebody approaches you and says "Hey, do you know what <insert name> said about you?". This guy is trying to get you to fight somebody for him. Your answer can only be "Let him say that to my face" and leave it at that. In general you never talk about other inmates when they are not around, part of the whole mind your own business mantra of prison.

Never go to the TV area if one exists. Fights always happen here over who gets to watch what, and often set ups happen where one group of inmates will be attacked by a rival group and you don't want to be caught in the middle while it all kicks off.

Finally, do not complain about the food or anything else out loud, or ever tell anybody when you are getting released. Guys who brag how they only have a few months left or are getting out the next week will have some guy who's doing decades or life immediately smash them because they don't want to be reminded of how much time they have. There will also be guys who simply want to mess with your release date and try to cause trouble because they can.

If you want to impress your fellow inmates, screw the system as much as possible like demanding a Kosher meal (often it's better quality food), orchestrating transfers, finding ways to weasel out of bad work detail. Anything you can figure out that gets one over on the system is respected.

tl;dr generally prison is not hollywood unless you're in a gang or owe money to drug dealers. For the most part you will just be doing time and bored stiff so get somebody to mail you TAOCP to do by hand, I wish I had that instead of the dismal prison library. Keep eyes forward, look at people's hands who are approaching you not their eyes.