I [16 M] [Socially Anxious] has crush on girl [16 F] and don't know how to approach her

Category: Dating + Personal Issues Well, I'm [16M] (suppose I'm Alex) living in England right now and if you haven't guessed already, I'm a student. However, I'm from country X, and this girl [16F] (lets call her Sheila) is from country Y, not far away from X. When I grew up in "X", my first language was English and I can't speak the language that the people from X mostly speak. Sheila, from country Y, speaks English and tends to hangout with the 'less popular' girls sometimes but sometimes I see her with the 'pretty' ones as well. She looks nice and judging by her looks (I know it's wrong), she seems decent and there's a good chance she's a nice person.

The thing is, I'm afraid of talking to someone whose popular because my social skills aren't great (they're terrible, I'm shy, I have high levels of social anxiety). The popular ones tend to have fitter boyfriends, prettier girlfriends, and better conversations. I've known to be a person among my peers to barely talk and have any input. My friends have always complained about that and I've genuinely tried to be a more interesting person, sadly I never found myself improving so I gave up.

I only tried talking to a (not-pretty) girl of my age, who is not popular and is not very good at English. I did manage to make friends with her but I have no feelings for her whatsoever (basically it was my first time trying to talk to a girl and improving my social skills). I usually sit around in a room most of the time (on the internet, gaming etc.) when I have not much to do and I'm quite lazy. As you know, because of anxiety I struggle in social events, especially in crowds when I'm afraid that people will judge me. I'm also afraid of my friends, who would interfere when I start talking to a girl (not that they have done it before, but I can see that happening) and probably try embarrassing me, which is one of my greatest fears. Some of my true friends have always told me whenever something embarrassing happens that "nobody cares", but inside, my heart is throbbing at unhealthy rates because I'm afraid of the countless people that will judge me. I'm not handsome at all, but I'm probably one of the most friendly guys and physically normal (I'm not mental, no) with good English. Sheila also speaks English but I've never spoken to her and I'm afraid of how people will judge me. The only advantage I have over the other guys is that I have a similar nationality and race compared to Sheila, and we both speak English.

Besides, when I talk to her, and she asks me for my hobbies, should I be totally honest about it? I don't read anymore, or watch television, and I probably have a boring-ass nerd life. I don't know whether I should just walk up to her and say "hi, I'm Alex, nice to meet you" (then shake hands). I have no idea what else to do or say, and my mind is so limited, you'd get the idea if you've met boring people before. If you think my life should change, please do say so, but understand that change is not as simple as telling yourself to commit.

I don't know whether I should go for it, as I have a little confidence left in the bottle and Sheila is a girl that some other guys fancy. My friend has assured me that she's not popular, but I've seen her with different people so I'm not so sure. I've missed my chance once and I don't see her often, but when I do, I feel like we're in the same situation, that we could be together... but all these hopes are being crushed by the fact that other guys actually like her and even my friend does as well (although his English is not great). Everyone around me is so confident, may have better conversations, but are not very smart and not as mature. Even if she wasn't my girlfriend she'd be a great friend if she was nice. Sometimes I hate my friends because they're not nice enough.

tl;dr: I'm a socially anxious boy who speaks the same language and has the same nationality as this girl but struggles in social events and doesn't know how to approach a girl and what to say. I'm abnormally a nice person and my conversational skills are beyond bad. I do like this girl as I've been trying to find someone like her, and in my school she is one of a kind.

So, after writing all this, all I'm asking is three questions: How do I improve my social/conversational skills? Should I talk to her or just leave relationships until I actually become more mature? And if I do talk to her, what should I say?

EDIT*: Can't assign more than 1 flair, but this does go under "personal issues" and "dating" I think.