Currently I have installed fluka and flair. what information is available for me to quickly get started with fluka, and implement some energy spectrum calculations?
if you have installed the CERN version I would suggest to start at: https://indico.cern.ch/event/1123370/ . You can download all the material and start reviewing them while trying the exercises.
If you got the www.fluka.org version, I found this: https://indico.cern.ch/event/753612/timetable/#20190408
Both sessions should be enough to get you started.