Rocket launch.

IF you can get onto the base, spend the money! We watched one of the night shuttle shots from the the causeway and what a thrill. We also were at the Space Park (with about 100,000 of our friends) to see Musk launch his Tesla and then see the two fuel cells land back on the Cape. These events make one feel pretty small.
Also, if you can, check into a day on the Cape for tours and lunch with the moon rocket. It's been years, but I'm sure they still have attractions to see and do.
We have family in central Florida that we visit (free food and sleeping) so we've been able to see about a dozen launches up close and from a few miles away. Enjoy!!

Difficult to plan for a launch as its rather common for the specified date to slip a few days. Much easier if you can plan to stay for several days past expected launch date.

Veterans Memorial Park, also called Space View Park is a great place to watch from. With a pair of binos, we could see the launch pad (#39 I believe) across the water. When we were there, a local had set up and explained everything that was happening.

We watched two shuttle launches ...both were the Endeavor

We parked in parking lot catty-corner of MacDonald's in Titusville

Manatee Hammock campground is right across from the launch pads. They even have a sound feed and viewing area for the launches along with a posted schedule at the office.

It's all over in about 2 minutes but is something to experience. We saw it from the side of the road across a lagoon.

Pick a night launch if you can. There is a campground with a clear view. Jetty Park Campground.

If you wish to be closer I think you can get "tickets" to park on the side of the causeway.

Where in south Florida are they launching