First off, I was wondering how long it takes for you to come up with funny stuff for your replies and drawings, because when I try to think of hilarious comebacks I just stand there and stammer. Second, this has nothing to do with people I have crushes on, hooray! I start school in a few weeks, and last year all I did was mindlessly say "hey, do you like this thing? Oh. Bye." Seriously, my conversational skills are as bad as my eyesight, which is terrible. All the guides I read, as well as all everyone tells me is "just go and talk to people, it's easy and you surely know how to act! Go up and speak to classmates who are already friends and they'll be happy to see you! Act against your whole personality, smiley face!" How do I go talk to my classmates who already know each other and have formed friendships?
From, 'This Nickname is Currently Unavailable'
I spend a while on this stuff, TNiCU, because I am not a natural comedian like my boss (whom I sometimes claim is a person named Mean Uncle Sparknotes, but actually isn't). More to the point, I was exactly like you through the first few years of high school; I was awful at conversation (see graphic) and everyone else had known each other from a middle school I didn't go to. They'd have conversations like "Did you see what Grady did??" "Yeah, well, you know Grady!" and I'd be like "Ha, yeah, that Gravy, what a card!" and they would just frown at me with disdain. But this was before I became the expert conversationalist I am today (that is, I am often able to order coffee without staring at my shoes).
My point is that I can commiserate with you. In a high school situation where everyone has cliques and in-jokes and you have no idea what's going on, you feel like you might as well just start every conversation with "Hello! Well this conversation is going to be pointless so how about I shoot myself in the brain." But part of the problem is that feeling this way is a self-fulfilling prophecy. When you interact with someone and your whole mindset is "I have huge glasses and cannot talk," you're going to feel like a dork, which will in turn make you act like a dork. I can't overstate how important it is to enter a conversation honestly believing that you are awesome. I've quoted this study before, but something as simple as confident posture (as opposed to slouchy saddo posture) makes people earnestly rate themselves, on paper, as smarter/better/whatever. Your frame of mind is crucial here.
But of course I'm not just going to tell you "be more awesome" and cross my arms and conclude this post. Here are some other tips that helped me, and that I'm sure will help you.
Start with general questions or observations.
People joke about "So how about the weather" being a terribly bland conversation-starter, but it's a lot better than sprinting up do someone, arms flailing, and saying "HELLO DO YOU LIKE THE SAME ANIMES AS ME." Once you find you do have common ground, you can gush over its awesomeness all you want, but you shouldn't lead with that. Talk about classes, teachers, or any other stuff (school-related or not) that you definitely have in common. The point is to talk for a bit so that the other person is like, "Okay this girl is normal and not a weirdo," at which point you can start gauging what interests you have in common. Cliquishness is annoying, but doing this is how you overcome it—you meet, and bond with, one person, and then she introduces you to her friends, and eventually you feel like less of an outsider.
Ask followup questions.
Ideally, you should lead with topics that lend themselves to further conversation, but even if you do approach someone by demanding to know if he is into your animes, and he says no, then you can always grab him by the collar and shake him and insist to know which animes he does watch (note: do not actually do it this way). But whether you're talking about anime or school or anything else, pay attention to the other person. When you're focusing entirely on what the other person is saying, you cease to think "wahh I am a sad nerd" because you're busy thinking "well that show sounds interesting!" This is also how you figure out what follow-up questions to ask, because doing that is a natural result of being genuinely curious. As an added bonus, you get to know people better. Just don't fire off a million rapid-fire questions like you are a game show bonus round and you'll be fine.
If a group is excluding you, you're allowed to bail.
Don't become a human doormat for the sake of making friends, don't follow someone around like a puppy trying to make a friendly connection, and don't feel like you have to contribute to a conversation among people who relentlessly talk about things or people you don't know. A lot of my friends work together, and when they all start talking about their boss or something, I don't shout "SO I WAS PLAYING THIS VIDEO GAME AND-" until I've steered the conversation back to me. At that point, you can stick around if you want to, but you don't have to if it's making you feel completely ignored. The more you solidify individual friendships, though, the less likely this is to happen.
For the record, this situation is not entirely your fault. It's a normal human thing to want to talk about shared experiences and to gossip a bit (according to a Science Man, gossip is actually necessary to the social order). But once you find some kind of common ground with one person, you can gradually become more familiar with her group of friends until you don't feel like the fifth wheel anymore. You should never feel like you're acting against your whole personality; instead, you should just try to be super curious about other people, which will lead to wanting to know more about them, which is the best way to approach someone without feeling nervous about it.