Starting from scratch

My 2c...

1) Basic electrical theory. Nothing complicated but an understanding of voltage, amps, resistance, wire sizes, circuit protection (breakers, fuses, solid state protective devices, etc.) and SAFETY.  Sounds like you recognize this need.

2) Learn the different Train control systems (TMCC, DCS, conventional, bluetooth, etc. ), the components and wiring methods needed to be successful (esp in the command environment).

3) Your basic layout goal - which it sounds like you've reached one.  No need to jump in spending $1000s on stuff you'll regret buying later.  Start small, get the basics, grow later. 

4) Carpentry skills (basic layout construction methods).  Understanding grades and limitations of your model trains (if you plan on multiple levels). Layout location needs - low humidity, accessibility, lighting, potential water issues (basement), temperature (attic).

5) Understanding track arrangements - what will work for curve radii with the type of equipment you want (and hope) to run and your layout goals. 

6) Modeling goals such as Scale vs tinplate, Freelance vs prototype scenes, loop running vs switching, scratch building, etc.

7) Other aspects of the hobby such as: Restoring older equipment, upgrading new electronic stuff, prototype or historical research, join a local train club or historical organization, getting your kids involved, etc etc.

Have fun!

That’ll keep be busy for a while.

Many thanks, Bill

Best thing you could do is seek out local train enthusiasts.  Any clubs near you?  May be more challenging to find 3 rail people.  I'm here in central Indiana and advising a few new 3 railers.  Join NMRA.  That will connect you to other experienced model railroaders--maybe even a few 3 railers there.

Wow. The NMRA beginners guide is awesome. Thanks for sharing. Looks like I’ll be spending the next several months there.

Thanks again, Bill