My favorite place to walk since I have been here in Florida is a small park on the Intercoastal Waterway in Venice, Florida named Shamrock Park. I started walking here because it was very close to a home we were renting in Venice prior to us finding our permanent home in North Port. This park is about a 15-20 minute ride from North Port, so I still try to go there regularly to do my 5 mile walk. The park offers biking on the Legacy Trail, hiking on the paved and backwoods footpaths, tennis and basketball courts, a playground for children, and a really nice nature center.
I mainly enjoy the backwoods trails where you can see some wildlife, and hike on the small sand dunes near the Intercoastal Waterway. Some of the wildlife that I have seen include gopher turtles, lots of lizards, snakes, bobcats, and birds. There are boats to watch going along on the Intercoastal Waterway, and a small canal within the park where alligators have been spotted from time to time.

Intercoastal Waterway

Backwoods Section

Gopher Turtle
The park is also near the Venice airport, so you will see a lot of small aircraft flying around on a nice day. Across the Intercoastal Waterway from the park is Caspersen Beach which is on the Gulf of Mexico.
Below is a video I shot of me hiking in Shamrock Park, it will give you a full tour.