Things I wish I would have known before my first Pinburgh:
1) Get comfortable with EMs and early solid state games. Modern DMD games aren't as prevalent as you think at Pinburgh. You will be playing on an EM and probably 2 older solid state games each round, and likely just one DMD per round.
2) Look at tutorials and rule sheets. Watch Bowen's tutorials. But, keep in mind that on these machines, you're probably not going to be able to play like he does.
3) Practice with 2-ball games. As in, set the games to 2 balls, or just let your first or second ball drain. You will have tons of house balls at Pinburgh, and learning to deal with that instead of getting frustrated is key
4) Play as many different machines as you can, but keep switching it up to avoid getting too much into the groove of one machine. The AC/DC you play at Pinburgh will play nothing like the one you're dialed in to on your home turf.
5) At Pinburgh, take the time to read the rule cards if you're unfamiliar with the game. Watch other players in your group and learn from them as they play. Often, there will be shots that are safer than the others, and ways you can exploit features (like lit spinners on EMs) for bigger points. You may just be chopping wood. It's a totally different way to play.
6) Keep an open ear during the breaks. Everyone will be talking about the one that got away, or how difficult a certain machine was. This is beneficial in 2 ways: you will learn about some peculiarities of some games and you will also find that everyone else is having just as hard of a time as you are