Good start!
Couple quick suggestions: (Dont take offense to these, please! To be a better writer you have to take the good and bad input =)

When introducing the 'classes' of sl, try to be more fluid in your description. Not sure what your goal is here but what you have now sounds like the back of the Starlegends gamebox youd see at gamestop. It sounds like you want to write more of a story-type thing here, and to do that you want to create a believable universe for your reader to immerse themselves in. Instead of saying the three classes are blahblahblah, try something like this:
An elite and essential piece of the blackstar security force are the so-called commandos. Trained from birth to be human tanks, there are few forces in the universe that could topple one of these formidable soldiers.

Also, try to keep 'i'll' 'me' 'you' etc out of you story. this disconnects your reader from your fantasy/sci fi universe and reminds them they are reading a story. This technique can be used very effictively in some stories, but id guess a scifi novel based on star legebds would not be one of them. I know its hard, but pick another perspective and stick with it!

I had some more to pitch in here but kiddos r screamin and i gotta run - ill try to edit in more later