Can voltage and current be stepped up and connected together
Depends on what you mean by "utilize".  Beyond that whole second law of thermodynamics thing, each converter will be in the 75% - 90% efficient range.  If each is 80% efficient, then for every 100 W into the first converter you will get only 64 W out of the second converter.  Sketch a basic wiring diagram of what you want to try, write in some input voltages and currents, and see what the outputs are.