How To Enable Debug Mode From ADB Shell or ADB Via Terminal In Linux
You can't make use of ADB without turning on the Debugging mode. There is one way to access partitions via ADB even if you don't have ADB turned on. If you want to run ls on restricted partitions, like cd data, you need to boot (not flash) into a custom recovery. Asssuming that you have an unlocked device, run fastboot boot &lt;recovery.img&gt;.
Now that you have successfully booted into a custom recovery, mount relevant partitions and run adb commands.