I need help with a problem!

I made a game at a camp I went to and it’s done! I wanted to take it home, so I built it and saved the file on my usb. When I got home, the game wasn’t working. I realised that this was because the computers at the camp were macs and I have a pc. So I went on my account I used for the camp to build it for pc instead, but the project wasn’t there!

I don’t know why it’s not showing up, but I hope someone on this forum does!

This really doesn’t sound like a Unity question - nobody here can help you access a project you saved on a different computer. You need to contact your camp and ask them to send you a package of the project - not the build - and you’ll be able to build it on your PC at home.