My new Mac says that photos is taking up 30mb but I don't have any pictures?

Perhaps the system hides various standard screen images

within Photos application, for reference; as it has in past?

While I've found those in previous versions Photos/iPhoto

the macOS system has kept them aside from user content.

..Maybe someone else may offer ideas? Take care.!

a typical /Applications folder in recent MacOS is around 30,000 M Bytes (even larger with Xcode installed as well).

Don't obsess over 30 M Bytes of stray files characterized as "Pictures".