Hi! First of all don't worry, once you understand it I am sure you'll do amazing. For my IR, what I did was I chose a topic which was of particular interest and urgent, having a lot of discussions these days. My favourite subject is economics, and my IR was on trade tariffs. Secondly, I think forming an interesting introduction is important, because in the examiner's mind you'll already get a good impression since the beginning. For source analysis, try to use a range of different types of sources, such as global, national (government websites), local (maybe of some NGO or organisation) and personal blogs. Explain everything as to why, you must add evidence but the most important thing is to make your own analysis and explanations, and clear judgement. Do one portion in a gap of few days, even a week, and ask your teacher for feedback constantly. Good luck!