Dear Madavaram, Yes it is better to start preparation from the first year but I'm not suggested to you because this is the first year of  your college at this time you will enjoy little bit because after that you may not get time to enjoy your college life at this movement you should make a friend who has the same kind of dream, at time you need to know about your future option make goal and made path this all done in the first year. That its.

All the best.

Hi buddy, This is your first year you should focus on college life. There are many things to do in college, there are events, fest etc. Participate in those events and fest witj full enthusiasm. If you are truly inclined towards gate you should go for it 2nd year onwards. Most of the students study onky in 4th year and clear it. You should start 2nd year onwards to avoid extra burden in final year. 

This is my personal view. It may differ from preson to person but final choice lies with you. All the best.