hi,

see there is various website is available which has free video lectures of IAS or civil service preparation. however there is many coaching institute who are taking online classes, you have to be very selective and compare the classes as per the standards of questions and lectures provided. you may follow byjus,  chanakyaacademy lectures.

however you can not just depends on online ,lectures, you have to study from the books, for gk questions follow the daily newspaper, analyse the previous years papers to know about the difficulty level,

to get the few tips to prepare for the exam follow our article:

https://competition.careers360.com/articles/how-prepare-for-upsc-ias