Fire fighters get a lot of overhead lifting. Ladders and getting equipment in position. Pulling for setting up hoses and platforms to work from. Holding strength is very import with that overhead and pulling motion. Also holding strength just to keep and move a high powered fire hose for long periods (at times a two man job). If you work for a forest or mountain fire department, than your working in very rugged conditions. Those crews go through hell when it's 100 degrees, or more, in SoCal. Plus the added weight of the suit and extra equipment that must be worn. And than your dragging long, very heavy hoses up those inclines to get to the fire control lines.
AS far as training goes, I might suggest stamina type exercises(endurance and strength). Something like clean & press/jerks, cleans, snatches, squat cleans, squats, DL's, STDL's. All forms of overhead presses; front and PBN's. DB presses included also. UPright rows, with BB and or DB's, etc. Firemen have a lot of one arm pressing and pulling work to do at times, so DB's should be included in workouts. A extra strong grip will be very helpful.Some duty firemen will run the fire trails, with a service pack, for extra leg stamina. I have heard of one guy who would run with a full fire suit on, but only at the cooler time of year. Don't worry about looking pretty like a BB'er. You want functional strength for a very demanding job.
Iilwoday gives very good advise. Get some class time in, that's going to help a lot. After you get on a fire department steady, there will be weight training facilities available. And they do eat well. Can on hard on a married guy though. Good Luck.
Side Bar: A guy I went to high school with was in the 101st AirBorne and than got on with the US forest dept. (he had to relearn everything he learned about jumping while in the army) He was a smoke jumper for awhile in Montana. Last I seen him he was stationed at a fire watch tower in Idaho. He loved that kind of life and some of his stories could be made into a movie. Great life if you don't weaken.,