You must start the round within 10 minutes of the announced start, or you can be disqualified.
There is a 60 second intentional delay of game rule in the Papa Rulebook, you should review.
Real world answer:
Don't worry too much about it. If you don't know the machine at the start of the round, no cramming is really going to help. Figure out 1 or 2 simple objectives, like get multi-ball or qualify a jackpot. Stick with those, and don't get fancy. The machines are set up way harder than you have ever played them, so odds of you getting through a lot of different scenarios are low. You will be thrashing a lot, so just keep it alive.
If this is your first Pinburgh, I'd apply that real world answer to about everything for the weekend. Don't worry about it, you aren't going to win, so just enjoy the experience.
Don't worry about all the intricacies of the tournament, it will all make sense when you are there. Just show up on time, wear good shoes, drink lots of water, and you'll have a great time.