There are no ready language files, but the theme becomes a multilingual one in few moments! You can translate it into German, French, Italian, Portuguese, Russian, Spanish, Turkish or any other language. It's RTL ready, so you may add a plugin and change the theme content to be shown as RTL.
This procedure needs some time and patience from you.

First thing you should do is create your own language file. To implement this you should install Poedit:
www.poedit.net

For instance, here's how it will look like for Riviera theme - you need to copy riviera.pot file to your computer.

Note: You will find the language pot file in wp-content/themes/riviera/framework/languages.

Run Poedit and go to File/New catalog from POT file.

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Choose the .pot file you've copied to use as a skeleton of your language. You'll get the list of messages and common phrases. Select a text you'd like to translate onto your language and enter changes in a lower field as shown on the screenshot:

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You should enter new text to the field in the bottom of the window - it will be saved for each item automatically. Edit all the messages you need and save changes to the file before closing. Please, create, for instance the lg_LG file (or any other name by your suggestion). The program will create two files with similar names: .po and .mo.

When the translation is finished and saved, copy these two files to your server: wp-content/themes/Riviera/theme/languages. Add the new file's name to your wp-config.php file inside of empty quotes in the line

define('WPLANG', ");

to make it look like this:

define('WPLANG', 'lg_LG');

In this line lg_LG is a sample code of any language you'd like to set.

Note: Don't enter a file type to the line. For example, define('WPLANG', 'lg_LG.po') is incorrect!

Here is a list of language codes examples, which you can use:
de_DE means to translate your site into German
fr_FR means to translate into French
it_IT means Italian
pt_PT means to translate into Portuguese
es_ES means to translate your site into Spanish
ru_RU means to translate into Russian
and so on.

But the way your language is called is not that fundamental. Use letters or numbers - no matter. Just make sure you typed it correctly in wp-config.
You still can edit these files without a single problem! If you open a lg_LG.po with Poedit, you'll get the following list:

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As about Contact Form texts, they are located in the language files of the Form Builder plugin, not the entire theme.
You can find them at: wp-content/plugins/contact-form-builder/languages