need help finding a book i read when i was a teenager

so i have been wanting to read this book that i checked out at my local library when i was still in school. i tried checking my checkout history but since i moved it goes back about two months, so it was not helpful.

what i can remember from the book is that the main character’s name (i think) was hannah and her best friend, oliver (?) called her ghost as a nickname. they have never met, hannah’s older sister i think used to date oliver’s older brother or friend and that’s how they got introduced. they have only seen each other over video call. hannah goes to vegas on a whim to go meet oliver for the first time with her sister and best friend. oliver’s brother and his friends are in a band, oliver had led hannah to believe he was in the band but he’s actually the songwriter for them. hannah goes to surprise him at a concert, finds out he’s not the singer, and also finds out he has a girlfriend, frankie (?). i know that hannah goes on a rollercoaster for the first time on the way home from vegas after a lot of stuff happens and they turn around for some reason to go see oliver’s brother’s band perform in the backyard of their house and when they finally kiss at the end she’s all like “this is better than the rollercoaster”. i also remember that her girl best friend’s name is paloma, and she goes by lo. i *think*. i feel like the cover has a pair or yellow or blue headphones on it with a sound wave thing that makes a heart in the middle. i think i read this in 2018-2019. there’s also a scene where oliver and hannah are on the eiffel tower in vegas and almost kiss (?) and i know that those souvenir pennies are like one of their best friend things and it’s a theme of their friendship in the book.

literally anything will be helpful. just want to read this book again.