Do I have to introduce myself to this girl I'm planning to approach?

[alpyo]

I'm planning to approach this girl I kind of like. We met before, actually it was last year when three girls from her school (including her) and a girl, a boy and I went to one sort of school competition to the nearby city (it was kinda notional thing...). We didn't really talk much but I've remembered her name. What I want to know here is, if I approach her, is it good thing to introduce myself first or start talking and see if she remembered my name. One small problem here being that the teacher (she was from hers school) didn't introduce us with them and vice versa (probably because she didn't really had to lol), yet I still caught her name when she was checking who's absent.

I've already planned my opener, but should I say something like..."hy, have you been invited to xy competition this year too? btw do you remember me, I'm _____" or not?