a) I agree with Jessica, it doesn't need to align with your skills, but I think it always comes across better when you are able to back up your interest in a particular area with tangible experiences. This can be anything from maybe attending a presentation with a firm on a certain practice area, doing a module at university, or any work experience you've had. You could also think of this not just from the perspective of what type of legal deal it is (i.e. disputes/M&A/finance) but about what industry the deal touches on. So if its a deal in the pharmaceutical, automobile or retail industry for example - think about if you have any experiences that could help tie your interest to those areas.
b) Definitely just pick the side that interests you. However, if you feel worried about not having enough things to discuss some things you can consider when picking a side -
- Was there a non UK client/side? (if it involves an emerging market there could potentially be a lot to discuss in terms of emerging regulations and political complexities of executing the deal)
- Was there a side which needed the deal to go through because particularly of urgent commercial considerations? (maybe it was an investment in a new technology needed to keep up with competitors)
- Is it a particularly well known/big client? - could introduce further issues like confidentiality (particularly if it was a listed client)
Side note: If you are choosing an M&A deal/transactional deal, I'd say don't pick the side that's advising the banks just because lender documentation on these types of deals can be very standard and its usually the companies that have a lot of issues they want to push back on in negotiations.
c) Don't think this matters as much. If it is a well known deal you could find a lot of background information that could really help you go into detail but if it's an obscure one you might struggle slightly more.