Just press play. My first project with actually good audio and characters that I made (that also look terrible by the way). DONT DISRESPECT THE LIBRARIAN! Also, audio warning. RIP headphone users.
I finally found out how to get good audio sound effects. Here's the website I used if you want to use it: https://www.myinstants.com/en/index/us/ It is a good website, but there is some inappropriate stuff on there that shouldn't be used for Scratch.