Tips:
the thrust transform is created in UNITY not BLENDER
you can name it whatever as long as you mention it as the point the thrust comes out of in the thrust transform section
e.g if i name it "fire_here" i'd put thrusttransform = fire_here
blender is complex (its a bit like trying to write with a pen where your hand is at the top)
start with simple shapes i started with a cube (which also is default shape)
parts are game objects in unity
thrust transforms are children of game objects (if i can recall correctly)