I'm not one to say much about this, but try taking a die along instead of a regular coin or coin that's included in a theme deck. Most players use dice for coin flipping and damage counting (damage counting with dice isn't hard to understand). Simply roll the die whenever you're asked to flip a coin. Even numbers are heads, odd numbers are tails. I'm not sure what the standard is now for deciding who goes first with a die, so wait for an answer about that (fairly sure the person not rolling calls heads or tails, the roller rolls, and the outcome is decided).
As for other general prerelease advice, just make sure you have your POP ID (eh, I guess it's P!P ID now), dice, and poison and burn markers (not as crucial, but you should still have 1 of each if you can).