ortucis, first of all there is a difference between learning c# or javascript as a programming language and using the learned language for unity.

learning the language (syntax, commands, keywords) is fairly easy, just google "c# tutorial" or get yourself a book on amazon... they are as cheap as 10 bucks.
EDIT: you can compare this to learning a new language: you learn the grammatical rules first, which tell you how the vocabulary is used to make sense, after that you only need to learn the words.

after that, after having learned c# or javascript, the grammatical rules of the programming language, you need to learn how to use the commands that unity has in the language you learnt... and once you are at this point, you do not need to distinguish between javascript and c# any more.. javascript and c# use the commands in the same fashion..

c# has a few advantages over javascript, the most important of which is that you can use Visual Studio for programming - which - believe me - makes it a lot easier.