Hello Aspirant,

A1 -Beginner, A2- Elementary,B1-Intermediate and B2- Upper Intermediate. These are the levels and it is to be understood that learning a new language from scratch is not that easy. B2 level is where you will gain a decent fluency and lack of hesitation to speak. So it will depend upon your determination,eagerness and interest towards the language.So on an average rate or general sense, to go from A1 to B2 it may take around 1 year and above. It may go beyond that too depending upon how you are able to grasp or adapt to the language. If you are planning make a career out of it and earn well , you need to reach C level.You will have many job options after that.

All the best