The most popular foreign languages in my country is English, french and German. Every school teach English and me opinion it so great. You can learn new language, you can meet a new people from other countries, you can with films in this language, you can read a books and much more.
I'm use English for listening to music, reaing a books and short stories, as well as for myself.
There are several ways to learn a foreign language: in a classroom with teacher and self-study. Each of this ways has benefits and drawbacks.
When you i the class, you are in learning enviroment. You can have lively discussion with your classmates and with teacher. You can get imediate feed back almost any questions. Also you can work in pairs. But it had drawbacks: you can't work at own speed you have inconvenient time table.
Other way learn foreign language is self-study. This way have a lot of advantages: you can learn the language at their own speed and in a pleasant atmosphere, you can organize your time, what you like. But this way also have drawback: you deprive yourself of lively discussion, you can be disorganize and save session for later.
In my opinion, the bast way learn foreign language in classroom with tacher and classmates. Yes, it's difficult, but effective.