first, you really don’t need lightwave to make a model spaceship,.,.. or buy any other modeller,.
You have carrara,. and you have a basic ship made from splines,.. (IMO) (it would be better to work in Vertex models) but you can convert from splines to vertex once you’re happy with the shape,
Spline models can be a quick way to model a shape,. but vertex modelling will allow you to define, refine, and sculpt that basic shape, into what you want.
You could also create a space-ship like Garstor has done,. using the vertex modeller.
The basic principles of “Box Modelling are easy to learn,. and there are many box modelling tutorials on-line, (the application used doesn’t matter much) it;s the tools and processes used that are important.
You start with a Box,. or simple shape,. then extrude to create more geometry,.
When you combine that with the “symmetry” option enabled,. then you can select one side of an object, and extrude it out to form a Wing shape, and the symmetry will create the opposite wing as you work.
When you work with Box modelling,. you can switch the “Smooth” option, On and Off, to preview the moldel as a subdivision smoothed object,. then switch back to un-smoothed to continue modelling , or refine the model further.
hope that makes sense