Anywhere on the Indian River is good, though anything further north from 528 is slightly better/closer, so you may want to take the bee line to sleepy Titusville where there are plenty of parks to watch from but not much to do/shop/eat after the launch.
Well there are some things, but coco has more.
It’s a daytime and almost historic test launch, but it won’t be landing back at the pad.
I suspect it’ll draw slightly bigger crowds, but not huge ones a manned flights do, as NASA puts more propaganda into those flights. you probably won’t face much traffic until you get close to the freeway, or on US1 right after the launch, it’s often better to park on the west side and walk across to beat traffic on US1 FYI.
I suggest watching from Titusville then escaping south via barna av and then Grissom parkway to downtown coco if you want to stay on the coast. for more details on coco you can ask dagger what’s best in life, in coco.