the academics are department-specific.
the PT is going to be mental toughness tested by physical means. You will be smoked when they decide you will be and it will stop when they decide. They can't hit you, they can't kill you, and they can't keep you too much after five o'clock or they start having to deal with federal laws on overtime. This is the advice I give to new fire cadets.
check out www.crossfit.com and start working toward the WODs (workout of the day) Most are extremely difficult and are something to be worked toward. DO NOT try to kick ass the first few days, start learning techniques and figuring out where you stand physically. The conditioning is great and it translates to running endurance without mega distances. You should still do some running, just make sure you don't give yourself shin splints or a stress fracture––definite academy killer.
Overall, eat well, hydrate, PT to get better, not break yourself down. DO NOT get hurt, you can always do more PT tomorrow if you are not hurt, if you wash out due to injury, you may not be able to come back. If in doubt, slow down, rest, whatever it takes to stay healthy. The other side of the coin is you do not want to be dropped for lack of performance, but that shouldn't be an issue if you are still making gains and getting stronger.