It's about a $35-45 cab ride from the fort lauderdale amtrak station to Port Everglades.
Afaik both southbound trains get in to FLL around 5 or 6 pm. The Amtrak station also serves as a commuter rail station, so of traveling on a business day, it should have a fair amount of people around. (I grew up in FLL, road the commuter rail regularly, and drove past the rail staton very regularly. My parents live 5 minutes from PT. Everglades.
The much nicer route from the train station to the port is broward blvd to Andrews avene south to las olas, east to a1a, and south to the beach (if interested in seeing the shops and people on Las Olas (cute, semi fancy shopping and dining district). If you took Broward all the way east to the beach, you'd see the Atlantic for a few blocks as you came south. Either route might at something like $8 to your fare, but would give you a sense of FLL.