That is going to be a good sized layout indeed. Do share your track plan as you develop it, I'm curious.

So on the size and power - the size (feet) of track do NOT mean you need more power - its not the size of the layout but the number of simultaneously operating consumers (locos, lights, etc) that draw power and determine the additional needed power via boosters. For 12 locos, that will definitely be needed if running them all at the same time.

Basic recommendation - put any layout lighting and power for turnout movement and other non-"To a decoder" circuits on their own DC power supplies. Any readily available 12v-19v range supply will do, based on the voltages that are needed to power your lighting type or turnout motors. Save the digital controller power for the track to power locos and decoders.

Boosters - the boosters basically provide a fresh batch of power (Amps) and impose the digital data signal on that from the control system, but the track powered by a booster must be electrically isolated from the other track sections. Each main controller section and booster section needs to be isolated and only powered by the amp(booster/controller) assigned to it.

How you divide up your layout between boosters and your main controller can depend a lot on how the layout eventually works.

A common approach is to run a power bus wire (thicker gauge) under/along the track and feed smaller feed wires from the power bus to the track every x meters.
With boosters you want to have the power region they feed be meaningful and reduce unneeded wiring, so you may cover a section along a wall with one booster, or a square area with a booster, or the main station and yard with a booster. Its a geometry problem as well as a 'maintaining the wiring' problem. What would be easier to work with if you have to track a problem back to a broken power feed wire. Depends on the layout itself, not the size.

Maybe divide up the layout (once you have the main design of the track finished) based on a partitioning where at most some # of trains are in the section at once.
So if your thinking based on power (I haven't done the math so my number is just out of thin air) - that 3 full trains at most will consume the power from a single controller/booster, then divide your layout into sections where at most 3 trains will be in a section. So a long mainline run of one track in each direction may be a single booster. On the other hand, with an 4 platform main train station, one would divide the main station into multiple boosters if you consider there may be a train at every platform at the same time.

For wire, folks use different types. For long power runs, I'd favor a thicker multi-strand wire as it has some flexibility but also lower resistance than a single core solid wire. Think about wire colors - come up with a color code and use it; don't use one big spool of wire for everything - if its all the same color it really gets hard to work issues later.

The mobile station itself won't be able to power all of those 12 locos, lighting, etc by itself. You'll need boosters. But I'll let more experienced larger-layout folks answer definitively.

Switches - some folks do operate lights, turnouts, and turntables in an analog way (toggle switches or buttons) while running trains digital. If you think you will computer control, then maybe less analog switches and more control over digital devices that switch (which can come from various makers, as they can also be DCC controlled and still be commanded by your MS or CS or computer.

Thank you very much Minok and DaleSchulltz for your information...you are very kind!

I will need some time to process your answers, but I will back with some questions ...for sure. As far as I finish my layout plan, I will send you some images.

Thanks a lot again!

Carlos52