They actually come together to form a little minigame that Bungie created, it's called "Ultima Confusion X: What the fuck is all this?" and the reward for completing it is that they all piss off.
Throw all that shit in the bin and play with what you enjoy. If you tried to keep track of the metas and sort out the who's who of weapons and armour, you'd lose your mind. Find a gun you enjoy playing with and every time you get something else, play with it a bit and see if you enjoy it more, if not - infuse or bin. Keep one gun of each type for the various gunsmith bounties, and you're golden.
As for armour, I just randomly picked something I liked, maxed it out and masterworked it, then added some nice colours and shit so I look fucking fabulous darling and use that. If you want to fanny about min-maxing then hit up Youtube, shitloads of sweats who will tell you where to place every single pixel but I play the way I enjoy and if that means I do 5% less damage then so be it.