Crush advice

I'm a high schooler and I've liked this girl since the beginning of this school year. Things were going great at the start of the school year between us, but then I messed up and creeped her out since all I did was stare at her since I was too scared to make a move. I meant to apologize to her shortly after that happened, but that never did and things have been awkward between us ever since. Now it's almost the end of the school year and I want to apologize to this girl now, but I wouldn't even know what to say to her and how to approach her about it, or if I should even apologize to her in the first place. In some aspects this is about getting a second chance to be with her, but also just making things less awkward and right to make room for a possible friendship. What should I do?