- Go to Play store and search for App Lock.
- Download the application with this icon
- Download and Install it.
- Now, launch the application.
- Setup password and Recovery Questions.
- Now you can select the applications you wish to lock.
- You can also hide your pictures and video inside Vault.
To root your phone manually, you need to turn on USB Debugging.
XDA Developers is a great site to help you with the process, support and Custom ROMs.
Check the below video for One click root method that works on many latest devices:
You can find all the specs here: Nokia 2.2