A Licence will allow you to create multiple sets, and multiple translation languages.
Developers : If you are running from localhost then everything will work, but to use on a live site you will need a licence to translate more than one language.
You licence is valid, but it is not for the current domain
Your licence will work for the specified domain and subdomains (e.g. example.com, other.example.com) but it will not work for other domains with the same ending (e.g. myexample.com)
If you need translations for another site then you will need to purchase a new domain licence for that site.
Your instance of Translation Manager is running in localhost mode, with no restrictions.
If you move to a domain without a licence you will be limited to one set, and one target language