how do i start talking to him?

So if 你 saw my 前一个 entry, "does he like me... 或者 not?", 你 probably 说 he does indeed like me. If 你 haven't read it yet, then 你 should probably go and check it out so everything makes 更多 sense.

Two people 评论 saying that they assumed he liked me and I should try talking to him. Thing is... I don't necessarily know where to start. It's not like I'm a complete stranger to him - I've talked to him before, it's just that conversations don't go the way that I plan them too. Either we're too shy to say something else, 或者 someone barges in and takes the limelight, so he ends up talking to them and not me.
As I 说 before, this guy is one of the most 流行的 boys in school and he's extremely musically talented. He loves playing 钢琴 and preforming magic tricks. He's quite weird, actually, and he's pretty poetic. He likes 表演 and is probably one of the best singers I've ever heard for our age.
Again, I don't know what kind of topics to start talking about... I've always had this extremely high social anxiety level since I was bullied mercilessly in the past. I don't have any 老友记 (literally, I'm not exaggerating) and I find it hard to make friends. Let alone talk to the guy I like! So what can I do to start a conversation with him?