Something went wrong with your scale, it looks like you edited an preview image of objective global warship, done by erik_t as seen here,
http://www.shipbucket.com/forums/viewto ... 052#p29052, and decided to draw something on that. I am afraid the image, as it is now, is pretty much unusable for anything.
That said, 518 meters is longer then the largest floating object ever (that would be the Shell Prelude, at 488 meters) and sizes like this are somewhat harder to reach for a warship that has to be able to resist shocks and other abuse. In other words, it would be hard to make this thing float, let alone let it be useful.
At this point you have the option to start again, working on something this size, which is extremely difficult to get realistic and working for even the most experienced designers (as this is just not done in real life yet, if it will ever be done) or start with some stuff similar to what exists, or even by mastering the shipbucket style by picking an ship yet undrawn for the shipbucket archive and adding it before starting to learn how ships actually work. It's your choice, but you can see what I recommend
. You will get a lot of feedback on 'realistic' or 'real' ships in comparision with drawing superships like this one, so you will be able to learn faster as well.
I know this does not really match with nationstates though.........