Your site will translate into whatever languages you choose. The global setup will be handled by your OTC rep in AWS (or the person who manages your AWS account). Once done, you can access the translation area of the admin to decide which of your catalog labels and list labels will get automatically translated and which ones will remain in your base language (which is set in the BASIC SETTINGS area).
You may find that the AWS translation engine is not doing exactly what you need on labels that need translation. In this case, go to CUSTOM DICTIONARIES on the left menu where you can create individual word translations for any of your destination languages.