Pack some nice homemade food, cause this isn't a short trip !
There are direct trains but no direct flights for this journey. kolkata (West Bengal) to Tirupati (Andhra Pradesh) distance is 1629 km and you can get there by flight + flight in just over 6 hours or by train fares starting from ₹ 526.
The weather at Tirupati is varying from "nice" to "hotter than nice".