My advice
Forget applying to groundstaff if you want to be a flight attendant! Find any job that involves working with teams in a shiftwork environment and dealing very closely with customers. Customer service skills are EXTREMELY important. Working with a Bank / Teaching English in Japan etc are very good starts!
If you were in QF groundstaff there is a high chance it could work against you! I think even working at a Videostore or Maccas is a really really good start!