Hi and welcome to Trainz,
First: Do yourself a big favor and remove your email address from your post; you dont want spam-bots to find it and nuke you.
To reply to your actualy comment:
There are a bunch of routes out there which are regulary active. Check out the "Montana Rail Link" and the "UMR multiplayer" for the most active and large routes. For others, keep an eye out on this forum and dig through the topics.
To check if a route currently has multiplayer action, you only need to download the route; those active sessions will then pop up. Give the game a few minutes to sync though; it can take 5 minutes before they are found. The next thing would be to download the session via the Content Manager as that does not always work by just pressing "join".
To cover the most common problems with multiplayer:
Make 100% sure that your game is the last build (currently 49922 for TS12) and that the number of updates shown on the in-game screen is 0. If that is not the case, you can not play multiplayer and have to patch / update your game.
