Well the colors looks bit funky. Usually if the ship is supposed to be in uniformal same color, we do it so that the hull itself is bit darker shade than the upper works (superstructures eg.)
Also, never use black as to color something. If something is supposed to be "black", use dark (really dark) shade of grey instead.
Leave the black color to do the outlining. This also includes the bridge windows and portholes.
Use the standard railing. It should be found in the equipment sheets.
Try to implent these changes and then we see what to do next
Overally this isen't bad start at all if this is indeed your first drawing of this style.