Do not overthink or do not take much stress as you have already taken PCMB which itself has a huge bunch of syllabus. So first try to clear your 11th and 12th and then you can think for preparing.

After 12th you could take Arts stream which in turn will help in your preparation for UPSC CSE. And one more thing, it is a myth that you will have to remember the all only the dates and all. Yes, you will have to but slowly, slowly you will take up and there are also certain tricks to mug up those Historical Dates.

All the best!!

Hello,

See, upsc syllabus is quite vast and it's not just about history, but the key thing here is to start with NCERTs and then move towards standard books and keep the resources minimum because the best thing is to read a book many times, instead of many books one time, and UPSC isn't just about history, there are polity, geography, economics, science and technology etc, and don't worry about remembering things, the reason I'm saying this is once you start your preparation you will read so much ,that you will gain enough knowledge to put it down in the paper, yes, for that writing practice too counts, as you have complete one paper of 250 Mark's in three hours, you have to understand the key aspect of UPSC is not to be an expert but to grasp at least the decent understanding and strong foundation of the subjects.