Hi ChooChoo1972,
Also, if you visit the Lionel website you will instructional videos for wiring, products and other helpful tips.
You can also find manuals or user guides in .pdf form when you search and view various products. eg. FasTrack Terminal section
If the spade connectors have been removed from a factory power wire, you will find that one of the wires is smooth on the outside and one has ridges to help identify them.
Here is a ready-to-run set video. At 1:43, the terminal track and transformer connection is discussed.
Also, almost all FasTrack has terminals for power and common connections, although there is no slot for the wire to exit the roadbed.