At the beginning, nobody knew anything

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i feel like such a newbie!
OK I'm at the trainz download station. I have logged on.
In the "download Station Searches" section I suspect is where I would search for a route.
Talk me though a simple exercise of getting something.
I searched "mega", but maybe I need to be more basic.
One of the results is the "Travis Daily Coal Session", seems interesting... but there are dependencies?
Ok, So, How would I get this route and its dependencies, and more importanntly, How would I get them playable?
(Told you I was a newbie!)
Not sure where you are and because this also helps my brain:
- Start Trainz12.
- In the menu, go to the 3rd option: "Content".
- In the DLS (the thing now started), go to the top of the screen and select the "Download Station" tab.
- Go to the left of the screen, find "search", maybe open it by pressing ^.
- Press "+".
- Change "Name" to "Category".
- Optional: Press "+" a few more times and add stuff like "Obsolete = False" and "Out of date = False".
- Now I think by default the screen on the right does not show "Installation Date". To get that visible, right-click on one of the colom headers and select it.
- Order on that date by clicking on it. Might need to do that twice so the most recent date is at the top. This gives you the list of most recent altered / added routes so you run the least risk of getting old content with... well... lets call them "TS12 problems".
- Right click on the thing you want and select "download".
Congratz, you are now at the point stuff is starting to enter your PC. Depending on if you have a FCT this might take a few minutes or ages.
Think we now reached your actual question, but anyway...
- After the stuff is done downloading, clear the list on the left, go to the top of your screen and select "Missing Dependencies".
- In that list, right click on everything you see there and select "download", because for some reason the program could not find everything the first time.
- Repeat previous step a few times just to be sure.
If you are still missing stuff, see if you can just play the route without it; you usually can. If not, and cant live with that, return to the website and search for the KUIDs you are missing. But lets hope that does not happen any time soon.
Repeat the previous for finding a session. I advice you to then also enter (parts of) the name of the route you just downloaded to find related sessions.
Part 2, In the create session I can place consists, and drivers and change weather and all that, but where is the option to put an engine to drive?
So you managed to get the engines and cars on the track?
The most easy step now would be: Press <ctrl-F2>.
Can we make it more lazy... hmmm... yes we can! Press the "quick drive" icon in the top left corner.
Edit:
You will find the "mega route" by searching for "UMR".
If you do not have a First Class Ticket (FCT), I suggest you do not bother with UMR yet and start with something else, as the UMR is over 600mb which will take you a week without a FCT.