Current first-year here, but I found the interview last year to be pretty laid back. Then again, I felt all my MMI-format interviews were much easier than the non-MMI standard interviews, but some people think the opposite. There's not a whole lot you can do to prepare for MMIs, but I would find a mock MMI online (
https://multipleminiinterview.com/mmi-questions/) (couple of helpful vids on YT too) just so it's not a complete surprise. What I did the day before the interview was a 30min-1hr mock MMI just so I wasn't rusty, plus I reread my primary/CV and secondary applications and personal statement. Remember, there are no 'right' or 'wrong' answers, but sometimes you can gleam from the scenario the type of response you should give/qualities you should demonstrate. If you're chosen for the interview, you have one foot through the door. So be yourself and carry yourself well and you will definitely get that acceptance!