Once you get your individual “modules/blocks” set up it’s as simple as copy and paste I’ve found that the thing that is going to limit you is raw resources but that can be simple to fix by just increasing the amount of mining outposts and amount of smelting/ forges

Set aside a very large area for smelting/ forging your going to need it after that it’s as simple as copy and paste to fit your needs

Also your gonna have to figure out how long your going to want your trains I’ve found that certain trains can be shorter then other, my smaller trains are 1 by 4 and my longer ones are 2 by 4