As an Autistic Man, it is really irritating that, people, as though they are a Neurotypical person that expects me to easily "get" unspoken social rules, and easily understand things without needing background information, it seems as though I am for some reason expected to not only automatically understand what people talk about when they say those phrases, but also even if I do want to look them up, I am scared of doing it wrong, because growing up, my mom forbade me from socially interacting with people, which caused me to become socially awkward.... which made her not want me to talk to people for "Fear of embarrassing her", leading to a vicious cycle that caused me to never have any friends until last year.
So thus, even to this day, I am completely unfamiliar with what it means to Support a Local Community, to Go and Organize, to Read Theory.... unless those are all phrases that were made so memetically popular, that people forgot about their original meaning, and people repeat them in order to make themselves LOOK intelligent rather than actually say anything intelligent.
The end result? I have no clue whatsoever how to socialize with people, or to attend public events, how to know when they are happening, how to find them, I don't know what the first steps are with socializing.... all thanks to my mother, who failed to teach me social skills, and failed to teach me the confidence in helping myself.
So how do I accomplish the commonly thrown around phrases I just mentioned?
May I suggest casual hangouts for a bit before you jump into more tense, drama-filled political organizations then? It might be easier to start with a less stressful environment.
Try meetup.com, FB events, or local subreddits and look for local board game groups, hiking or biking groups, co-ed sports leagues, cocktail networking events, wine tasting tours, book clubs, little things like that. It's easier in my opinion if there's another activity like board games to help facilitate the social interaction. I also recommend finding hobbies or shows you're interested in and going to conventions based on them. You might have to travel a bit if you don't live near a big city. Going back to school can also help you meet people. For me, I'd also go to local bars and places every now and then, even by myself, and look for flyers for game nights or other things they may have.
I know it doesn't answer your other general questions about what organizing or reading theory means, but since one of your big worries seems to be in engaging in social interaction, that's probably where I'd recommend starting. If I'm off base, sorry about that, just trying to help.
I admit, at the moment, I was just giving in to peer pressure where my leftist friends think I don't seem "leftist" enough for them, so I am trying to prove to them that I am devoted to the cause, no matter how much it discomforts me. I was bullied once about it months ago, but I still don't want it to happen again.