Unfortunately, that's not available on WordPress.com.
You can, however, register as many blogs as you need under one account, so you could have one for each language. To do that, visit https://en.wordpress.com/signup/ while logged in.
Otherwise follow these steps on how to add a translation widget to your WordPress.com blog.
There are no restrictions if you setup a self-hosted WordPress.org blog instead of a WordPress.com blog, but there are some added responsibilities. We have hosting recommendations at the following link if you are interested.