finally confessing my feelings, please help me

19M first time confessing. Manghihingi lang sana advice kung pano magconfess. I recently asked a girl to come to a paskuhan concert with me and she said yes, i dont have an idea if she knows that i like her.

I am planning to confess within that day but i dont know when, should i say it before, during, or after the concert, because i also dont want to ruin the rest of the night and to make it awkward if i didn’t get the answer that i want. I also dont know wthat to say. please help. this is my first time so please bare with me