push and pull command return "push: not found"
By your words, I suppose that you're running adb within an adb shell and that's wrong. See this answer for more details.

In case I misunderstood your question:
On Android, adbd is by default not running as root, so certain files and directories are not visible to the ADB client. Still, refer to my answer for more details.

There is no such command as push or pull on your Android device. All you can do is adb push from your host PC. Whatever non-existent command makes shell tell you aaabbb: not found so it's not a bug.