My primary drive is disk3 in Disk Utility, is this right? Should I fix it?

Nothing to fix.

Totally normal.

It is a Container on the drive

Within that container are the other Volumes like the Macintosh HD - Data ( User Account data) , Macintosh HD Snapshot which is the Sealed and Read Only Volume where the Operating System Resides

This is from a M2 Apple Computer running Sonoma 14.3.1

Same thing on M2 MBA and M1 Desktop computer all running Sonoma 14.3.1

Welcome

Am current looking for a Full Drive Structure article as it pertains to Apple Silicon Computers

Once found, will post back.

Just for a fullness, in regards to your 😎

Found the article 👍

Though it applies to macOS 12 Monterey the drive structure is the same

https://eclecticlight.co/2021/12/16/boot-disk-layout-in-macos-monterey/