Do some running, get used to the workouts your school team typically does, and do some practice before hand so you are already warmed up. And make sure you stay healthy this year!
can i assume it's high school since very little schools in the US has a college badminton team? since you're in SoCal competition will be more fierce than that from NorCal. i would recommend you do do a bit of the chinese quick footwork you can find on youtube for warm up. swing your racket around to warm up your arm and upper body. most importantly, have fun, it's only high school (an assumption)!!!
Also make sure you are rested. Rest is more important than last minute practice. Other than that, nothing you can do will instantly make you a better player, it all comes with long-term practice.