Yes, you change the language by going to Settings -> System -> Language & input and change language here.
To switch between the different keyboards you have available on your HYDROGEN One, please follow the steps below:
Go to Settings > Languages and input and tap "Virtual Keyboard"
Tap Manage Keyboards
Enable the keyboards you installed
You may be prompted to enable permissions
To switch keyboards when entering text, click the keyboard icon in the very bottom right of the screen
Choose the desired keyboard.