Hi Jim,
I remember you from some time ago.
Surveyor is one of the easiest route building programs to use. Forget about anything you did in the past from RW, RS2015, or even MSTS. This will blow that away without even moving.
First let me say the best way to learn is to start small. As you probably know from other hobbies, you don't want grandeur plans to begin with and even then burn-out sits in, so let's start with a single baseboard.
This is essentially an overview because there's so much to it.
Start by creating a new route. You put in the name, choose the world location by choosing the location, and the measurement system. You can use model railroad scales, but everything is still 1:1 size, so choose Real Scale for now, and choose metric since all the measurements are in metric anyway.
You'll now see a grid. This is the base grid and is called a baseboard. A baseboard is 720m^2 and can be expanded. There is no smaller or larger size than 720 x 720, but other baseboards can be added on to the edges. The default height is at 0 meters. You change the height using the topology tool located in the upper right corner. Clicking on this tool reveals various knobs and dials. These adjust the size of your round brush, the quickness (sensitivity), and the height. You can also get height and enter in precise measurements if you wish. The add water lets you place water and type in precise height as well. Using a combination of the topology tools, setting lower heights, and placing water, you can put in lakes and rivers.
So, assuming you've played with these tools a bit, you'll notice an advanced button on the topology tool. You use this to add or remove baseboards and to use displacement maps, which we won't discuss now.
The next tool on the list on the right is textures. You change the size and pick the various grass, rock, sand, and other textures. By brushing briskly, you can blend textures into each other, producing a nice effect. By pressing the [ ] keys you can rotate the textures on the fly so they don't look like a piece of shag carpet.
Now down the list is the scenery objects and splines. Scenery objects are trees, houses, buildings, cars, etc. Splines, the next small tab on the same tool, is for telegraph poles, roads, and bridges. Placing objects is pretty straight forward. You simply choose and plop. There are some advanced tools associated with the splines, which include adding points, cutting sections, and raising and lowering them. I suggest you play with these tools. To place a spline, you simply click to start, drag the mouse and let go. If you want to add a parallel spline, press the shift key to prevent them from sticking to each other. If you need to keep your splines at the same height, such as for tracks, and bridges, you can click on the spline with the select spline tool. You can enter in an exact height, which is good for bridges, platforms, and even tunnels, by typing in the height and then using the apply height tool.
Moving on down the list, there is the track and trackside accessories tools. This tab contains all the spline-type tracks which you use to build your routes. The track will lay down like roads. You click in one place and drag, where you click, you'll see a spline point. If you click on that point, while adding track, your track will continue from there. It's pretty straight forward. The small tab to the right contains trackside objects such as signals, track junction levers, speed limit signs, crossing sights, and other stuff. They are placed by clicking on the track where you want them. Should they face the wrong direction, you can rotate them using the rotate function. Creating junctions is a simple connect and drag from an existing track spline.
On the same track objects pull-out, is track marks, triggers, and direction markers. These allow you to control train direction and paths. Track marks are named when you place them. When placed, a box opens up and you type in the name such as Up line to Radford. This will now show up in a list of track mark destinations when setting up a session. Direction markers are similar to one-way signs and are used to have AI drivers take a specific route and only that route. We use lots of those to keep the AI on-track, pun intended. Triggers are used for events and without going into too many details now, you use them for example to have a shunter locomotive pull out of a siding after your main line train has pulled into a siding, uncoupled from the rake, and then pulled into the engine house lead.
The other tools, very quickly are for layers (looks like paper), copy and pasting textures and objects (spanner), and finally placing of trains and consists (a wheel).
I hope this overview helps. There are some older videos on YouTube, done by Rob Shaw, that explain a lot of this in more detail. He made these for the earlier versions of Trainz, but the same interface and same concepts still apply.
John