can't use adb shell in recovery mode
You have a stock recovery. Try to boot to fastboot, using ADB: Apply this command in ADB while in recovery: adb reboot-bootloader, or: adb reboot bootloader. Try each one, if the first works, good. Check if the device is visible by fastboot devices. If it outputs nothing, try the other command. It should work now.

Now you have to flash the recovery using fastboot flashing abilities. After that, try again.