Welcome to the forum!
No need to be scared of anything pertaining to Lionel trains, as there are many people out there to help you in anything you may encounter with your trains.

First recommendation is to not even think about plugging in the transformer if the AC power cord is brittle, **** or in other than perfect condition. If  the cord needs replacement and you are capable of doing the job properly and safely, go to it. If not, a trip to your local repair shop is in order.

The picture shows the voltages available from the various terminal configurations. Terminals B-U giving 10-18 volts would be the place to start to run your trains. The conventional hookup is to connect the 'U' terminal to the outside rail, and the 'B' terminal to the center rail, although the transformer can be hooked up the other way also. The trains will run properly with either hookup.

Be aware that the transformer may not have a circuit breaker to protect itself from a short circuit or overload condition. An external automotive 12 volt@ 6amp breaker should be wired in series with the 'B' wire to the track.

Larry



[ Attachment Invalid Or Does Not Exist ]