How the heck does this work and what the heck can it do please help thanks

https://www.youtube.com/watch?v=o6_PbH_63z4
 

It is a soft synth, a sample playback synth.  It comes loaded with Programs (patches in synth speak). 
 
You insert it into a DAW - or standalone.  Read the manual for your DAW if the former.
 
You choose a program - a sound.  Read the manual.  Play a sound for an external midi keyboard.  Read that manual and set it up.  Record the sound and proceed with your song construction.
 
It may seem like a lot of reading, but it does take time.
 
@

LOOK!!!
Up in the sky! "It's a bird, It's a plane!"
Beezus Krust. Its NOT Me-Shell Backman?
"It's a Baker!"
Its CAKEWALK!!!

could be a biblical reference perhaps....added in.