If you are planning to view the Atlas V launch of NASA’s RBSP Atlas V spacecraft on Friday then by far the best place off Cape Canaveral AFS property is going to be on SR-401 behind Port Canaveral cruise docks where the launch complex is just over 11 miles away. There may be a few issues with buildings blocking the view of the pad from there, but a good view should be available if you move around a bit. The Xenon spotlights will guide you to the launch pad.
Failing that then the Max Brewer Bridge can offer a good view of the launch from the top of Titusville. It is 13 miles from the launch pad so the sound of the launch will not be great, but with the elevation you should be able to see the pad and get a great view of the launch. The pad should be lit up with Xenon spotlights, but if you look about half way between the VAB and LC-39A you should be able to see the LC-39 viewing platform and just to the left of that but further back is LC-41.
Normally the best place to watch an Atlas V launch is on Playalinda Beach but that will be shut as it is a night launch. The KSC often opens early for NASA launch viewing, but it is opening at 9am on launch day.
That just leaves the parks alongside Highway 1 North Washington Avenue as alternates if you dont want to travel to the SR401 or Max Brewer Bridge. The southernmost parks will give the best and closest views of the launch, but the actual launch pad may be obscured by vegetation. Kennedy Point park is probably the best of these with a view almost due east towards launch pad 41.
Remember to take plenty of liquid with you and of course insect repellant. The mossies can be brutal out there.