Not many part time firefighting jobs around unless you want to voulenteer. All the small cities around in the metroplex doesnt take part time firefighers. If you really want to voulenteer, you ahve to go out to places like Eagle Mountain Lake and Samson Park. Really small towns and its still hard to get in out there.
Most firefighter shifts are 24/48 shifts and not part time unless you are high up or voulenteer. Voulenteers basically come and go when they can. Training can be done at a few local firestations like North Richland Hills where they have their own burn building but you are better off going to a school like TCC and Weathorford with nice burn facilities to learn in. The classes are usually taught by firefighers anyways. Most stations are not hiring just firemen anymore, you have to be a firefighter/emt minimum and places like Grapevine Fire Department wont hire unless you are already certified firefighter/emt and are going for medic. Getting in the doors these days really hard. Pay for a fire/medic is usually around $35-40k starting and if can can do the 3 way thing police/fire/medic like in Southlake, you can make $60k+. Fire school is usually 1 full semester of school where you go 4-6 hours a day m-f.