Most people who appear for CAPF are the ones already preparing for Civil Services so the topics to be covered are almost the same. It was the same in my case as well. For starters, go through NCERTs from class 6u201312 of all relevant subjects, the topics and concepts are covered very well in them and all facts stated are fully accurate. Tata McGraw Hills book for Civil Services prelims MCQs is also very helpful. It's coverage of Indian National movement topic and Geography is good. Laxmikant for Polity, Mrunal u00bb Competitive exams Preparation for econonics and other topics, Vision IAS website's material for monthly current affairs and other current affairs topics, Unacademy by Roman Saini is also very good if you like watching videos for studies.Just be really thorough with topics you're preparing. It's better to go through same material again and again instead of referring to new materials. Second paper of CAPF has subjective questions, be sure to practice them and develop a good writing speed. I couldn't complete that paper as I hadn't practiced writing enough and had very bad writing speed. This actually brought down my rank. Practice English grammar questions as they're scoring. Apti and quant you'll find materials easily so I'm not getting into it, just practice it well to gain speed.Written part is comparitively easy to clear in CAPF. They don't keep the cut offs very high because they know that many people who have done exceptional in written fail to clear physical and medical rounds. So more people clear the written round in this exam. But written exam scores are very important for merit because that's what ultimately determines which force you'll be allotted.Try to score maximum in objective and do complete the written paper with good content, then success is yours. But remember that in CAPF, written exam is just the beginning. Don't forget about physical and medical part. Stay physically fit during your entire course of preparation. Most people get so carried away studying that they get obese during the process and no matter how good they might have performed in the written part, they fail in physical efficiency test.Interview is about originality. Fill up your biodata form, in UPSC terms, Detailed Application Form or DAF properly with genuine details. You can decide the flow of the interview and you can lead them to those exact topics that you want to talk about if whatever you've filled in your biodata form are genuine. The board has highly experienced people, mostly from ex Forces background so don't bluff, they're sure to look straight through you. Just stay calm with a smile, give balanced answers without drifting to either extremes or getting emotionally carried away by a certain issue.CAPF hence requires a balanced approach. Don't wait till the last minute to work on your physical fitness. You already know the criteria once notification is out so judge yourself accordingly and prepare. If you're overweight, do something about it gradually than expecting quick fix solutions at the last minute. After written exam be sure to practice all the physical test events in a simulated environment. You need to have good stamina as these events are conducted when it's around 11am and it's really sunny then, also you're made to do them back to back.I cleared the exam in 2022 so I'm not sure if things have changed much after that, this is just my opinion. All the best!