[Rukbat]

Are you trying to find out where your storage went? You should have 64GB, you add up all the sizes of apps, files, etc., you can find, and there's a lot apparently missing?

Install Terminal Emulator for Android. Run it. Type

df

and Enter. (If you turn the phone to landscape, it's easier to read.) Look for data or emulated at the end of a line. The first number is the number of 1k blocks of storage you have. Storage is partitioned, like a hard drive, but the only one you have access to is that last one. The rest are used for other things like, but not limited to, the OS.

But on some phones, more is partitioned for the system, or other partitions, so there's less left for you. That's just the way Android works.

(Can you repartition storage, the way you can repartition a hard drive? Not exactly, but it would take a pretty good knowledge of Linux to be able to do it, and if you had that knowledge, you wouldn't be asking. And yes, Android isn't an operating system, it's a program running in Linux [which is called the kernel in cellphone terminology].)