Hello,
First of all, choose a subject in your graduation which you find interesting, and there's eagerness within you to know more and more about that subject, it can be anything such as political science, history, geography, economics etc. and in order to appear for UPSC there's no restriction in terms of discipline or aggregate, and you need not worry that you'll be changing your stream, many people do that and yes, may be for two years you were not in touch with those subjects, but if your interest and curiosity is there you'll quickly grasp it and you have studied these subjects till 10th standard, it's not completely new to you in that sense,
Coming to UPSC, this is one of the toughest exam with an extensive syllabus, so the sooner you start your preparation, the better it is, I'll suggest you as you will enter your first year, start in a gradual manner, first of all make your foundation strong, take a print out of UPSC syllabus and go through it everyday, this is important as you'll get to know what to read and what to skip. Another important thing I'll recommend is start reading The Hindu everyday, this will not only make you aware of the latest happening but you'll also get to know viewpoints of so many prolific writers, these readings will further broaden your perspective, and when it comes to books, you should start with NCERTs, you need to be thorough with these books, and after this when you'll move towards the standards books then try to keep the resources minimum, and revision is the key here. These are the few tips just for your initial preparation. There are many more steps to follow afterwards, if you need any more information, you can ask me in the comment box below.
Hello student
Yes, you can opt for graduation with Arts stream without any problem.
If you score good marks, you may get selected for DU admission. So there is no problem that you are science student and pursue graduation with Arts. Go for it.
All the best.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile