From what I've read, you are only allowed to vape at the smoker's sections, but I don't have first hand experience. There's a couple of nice vape stores right around the parks if you were interested, need some juice, etc. I've driven past one of the Universal Studios entrances on the way to Orlando Vape & Ecig, 1 light and a turn away. About 5 minutes from that one is Vape & Brew. Both are pretty good, all though I've only visited them once or twice because I DIY. Vape & Brew serves has a small (beer) bar too.
Enjoy your trip!