There are a lot of good threads on doing deck plans, but the best place to start are with actual plans. I've collected a ton of plans of different naval vessels to help me get a feel for how to approach this type of project.
And don't discount the classic
Booklet of General Plans of the Enterprise, Franz Joseph's work built on naval standards. This can be seen in a comparison of the Booklet of General Plans of the USS Saratoga (CV-60) with Joseph's drawings...
I would suggest (at some future date) getting out to see some of these large naval vessels in person, specially the ones which are now museum ships, to get a feel for how big is
big. I grew up in Coronado were large carriers were omnipresent (namely the Constellation and Kitty Hawk), and it gave me a good point of reference.
Lastly, cross sections are very misleading. I've seen people scale up the size of their ships based on a cross section and not realized that they had provided the equivalent of a four bedroom apartment's amount of space for each crew person.
Hopefully something here is helpful.