How to confess??

there's was guy in my school, i remember his face surely, he was my first crush, well, i couldnt confess him that time also and left the place soon, now i'm in some other place and now i didnt imagine him appearing here, he didnt do it intensionally, and he didnt know that time too, so he has probably forgotten my face, now when ever i p him by in this new school i jst get scared and cant even ask him that if he is exactly that and was he there in whatever pplace it was...plzz tell me how to mutter my confidence and ask him and what shud be my first ques to him??? (he doesnt remember me but i do)