Well, there's the Miccosukee Casino on the west side off US 41 as you head out the Tamiami Trail.
On the north side in Davie there's the really big and really nice 595 Truck Stop at I-595 and US 441 right by the Florida Turnpike. That's definitely the best truck stop in South Florida, maybe all of Florida. If you're into shinny pretty things they've got an eye-popping chrome shop. Killer restaurant, too.
There are 3 PFJs down there. One is a "dealer" with like 20 parking spaces. That's at 16650 NW 27th Ave in Miami Gardens. The one at 12200 NW South River Drive in Medley has 65 spaces, and the Pilot across the street from the Miccosukee Casino has about 25 spaces.
In addition to the branded truck stop apps (which are
always up-to-date) like
MyPilot (Pilot Flying J),
TruckSmart (TA and Petro), and
Love's Connect, you should have on your phone the
MyDAT Trucker app, which besides load board information that's mostly useless for expediting, gives places to buy fuel and lists number of showers and parking spaces and other amenities. It also lists Walmart locations. (Those links are for Android phones, but the apps are available for the iPhones, too).