My 1989 chevy camero, automatic, v8 305 engine, is

My 1989 chevy camero, automatic, v8 305 engine, is acting funny. Brand new battery, water pump, brakes, tires, and trani mount. Has some wiring problems. Aparrently is wired backwards. It over heats alot. Put a new thermostat in and does not over heat as much but once in a while it will suddenly over heat. today i was at a stop light after exiting off the free way, and it suddenly just shut off. Turned it back on with a little trouble. Then started making funny noises. went to work and waited to look at it til i got off. Once i got off i started the car and took a little longer to turn over than usual. Once it started it made the funny noise again. But seemed to run fine. drove it home but once i put in park to open my gate, the noise was worse, temp rose to about 250 ish about ready to overheat. Opened the hood, the noise seems to be coming from the where the belt runs, somewhere in that general area. But its not the belt that is making the noise.also before this problem arose today, sometimes my car wont even start and its not the battery. It wont even turn over. but yesterday out of anger when it would not start i hit the starter, went to start my car and started with no problem at all. why wont it turn over? Can anyone tell me what can possibly be wrong with my camero? im a girl and dont know much about cars. konw the basics. but this is something that i need help with!!