To start a New Game, press 'New Game' or 'Instant Game' on the lower part of the main screen.
If you select 'New Game', you will be able to choose the language on the upper right corner of the screen. Pay attention when doing so, since once the game starts, it cannot be modified.
On the upper left corner of the screen, you will see a search bar to find your new opponent. Next to it, you'll see the option 'Invite Friends', which will allow you to invite your friends through the different apps you have on your device.
Keep in mind that if you don't select a friend as your opponent, another player will be randomly assigned to you.
If you select 'Instant Game', a game will be created with a random opponent.