What do I do?

Basically, my friends from school know that I've wanted a girlfriend for a while lol and I told them half-jokingly, find me one (I go to an all boys school lol). Well, one of my friends found a girl that he thought I'd be interested in and told me to follow her on Instagram, I have no clue how he knew about her cuz he doesn't actually follow her himself and she's private but he somehow had screenshots of her account lol. They made me follow her and are now telling me to add her on snapchat (her username is in the bio). But I am very hesitant about this because well, it's all a bit random, I've never seen this girl in real life (I didn't even know about her until they showed me her account), the only link I have is that she goes to the same school as my cousin and so adding her on snapchat just seems a bit weird (especially only 3 days after following her). But they're saying it's normal and I'm overthinking it, but am I really lol? I'm an extremely introverted person lol and very socially awkward, I don't have a clue what I'd actually say to her if I added her looool, and I'm pretty sure she'll just think I'm weird considering we've never interacted at all online, let alone irl. There are also a load of other things as well, I'm very insecure about many things (my looks, my dress sense, my personality, my interests lol) and I can't really think of why she'd find me attractive over other boys. I keep trying to delay adding her lol, but my friends message me every day asking 'have u added her yet?' and I actually feel like they're annoyed at me for not adding her and being so indecisive (at this point, I'm seriously considering adding her just so they don't get annoyed at me lol). I do think she's attractive ngl, and I kinda wish I could just add her and message her lol, but at the same time I feel like even if I did message her, nothing would actually happen (and that she'd think I was weird and told all her friends how 'some random creep' messaged her, which would be a problem, because I do know some people at that school thanks to my cousin going there). So, um, what do I do?

Paragraphs please 0_o