There are a few languages that would be good to know and would benefit you in the future. If your first language is English then one other language would benefit you no end.
The ones that you should look at are Spanish, the reason being is that there is a huge chunk of the world population that speak this language and their numbers are growing.
Chinese is important if you are dealing with manufacturing products as the Chinese companies head this sector. This would give your self an advantage over many of your competitors in this field. You could negotiate your own deals without having a translator.
Any language is good to know as it helps you communicate understanding the local people.