Firstly..Congratulations for getting placed.
As you have time to join in company..its better 4 u to start learning basics of programming.Although you may be given training for 3 months,but you just can't depend on it completely. To survive in the software field one has to have a passion to learn something new everyday.
Nothing late now..so start your learning as early as possible...so that once you are into your job you can cope up with your colleagues easily.
You can prefer online tutorials or any other way to start your learning.
So have a gud start..!!!