To add to the information that
N830MH has provided:
There is a no-charge shuttle that takes you from the Arrivals level (there are several pickup points along the curb (once you exit baggage claim, look for smallish signs marking the Tri-Rail pick-up spots). Time schedules are posted in the area of the signs.
The shuttle deposits you immediately at the entrance to the Dania Beach - Ft. Lauderdale Airport station. As you enter the station, there is a manned booth to the left, and automated machines on the right. Be aware that change for a USD 10 or USD 20 bill will be given in $1 coins, which are (unlike the Canadian $1 "Loonie" coins) NOT widely used in the US.
To prepare, be sure to study the train and shuttle schedules located on the Tri-Rail website:
http://tri-rail.com/rider_info/stati...dale%20AIRPORT