What are the steps or how do you start rebuilding a 1983 Chevy Suburban after a fire starting in or near the carburetor destroys the whole front end?

I don't know your situation, but it is HIGHLY UNLIKELY that you will be able to fix all the problems that the fire caused. The fire sounds like it was intense. this will make any repairs highly suspect and very expensive. Having said that, if you are dead set for rebuild, you might get a total front end from a junk yard. have them torch the front right off (frame and all). Then you can take all the parts off and put on yours.