1) It doesn't really matter. A mock exam to start gives you a good indicator of what to study and where your areas of weakness are, but a mock exam later means you get to do your first mock with confidence. It's up to you and how you learn. The most important thing is you actually doing a mock at some point.
2) There are some methods of pattern recognition that tutoring companies / learning packs tend to teach. They may help, but I think they are too rigid (partially also because I didn't use any of the above, and also because such a scaffold doesn't work for me). Doing a lot of practice questions is probably the best way unfortunately, because recognising as many patterns as possible and sticking them somewhere in your long-term memory is how you get quicker. Doing other mental exercises like those seen on psychometric tests (IQ tests, for example) might help as well. It's important to find a method that works for you early, then stick to it. It's such an easy question to ask, 'how can I improve' but is often inconclusive when someone tells you the answer because we all learn differently.
3) I don't actually remember too well, but you shouldn't need anything too complex. Proficiency in Year 9-10 maths should be enough to get by. Basic arithmetic is also key, I highly recommend doing arithmetic exercises to avoid having to use the on-screen calculator, which is an absolute joke. Topics I can definitely remember include percentages, decimals, fractions and reading off graphs.
4) Not necessarily. Perhaps over some, but definitely not all. There's only so much you can learn and prepare for UCAT, and your UCAT score sees diminishing increases the more you study past a certain point. Overstudying can actually lead to lower scores! As long as you're studying right and well you'll be fine, but if you start now it's highly likely you'll have to pay for additional resources at some point (which I'm sure you were prepared for anyway). Do your due research on paid packages now, if this is something you plan on investing in. The only thing I can guarantee is question familiarity, and when you do the actual exam a lot of circumstances actually change. It's like the saying that 'on derby day, form flies out the window'. Some people may also just learn quicker than you and overtake you in the process (which is not something you should be worried about, because that's the way the news goes sometimes).
So again, you will have the advantage because you are familiar with more questions, but you might not necessarily be superior in other exam necessities depending on how you prepare. This latter fact may or may not impact your score negatively; so be sure to study well and not push yourself too hard. It's great to see your enthusiasm though!
Hope this answers all your questions
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