The biggest issue you will have, as have I, is that people want VIP/Private experience. Usually a minimum of 2 years. And, it is a big of a vicious circle as you can not get a job to gain experience, because you don't have the experience, but no one will give you a change to get the experience in the first place.
I would recommend getting some catering training through a jet catering company, in one form or another. I am not suggesting taking a full VIP course, but you will find a lot of the better catering companies offer short day courses to Flight Attendants to help them with the catering side of the job, which is the biggest part of it.
Most jobs are not advertised, but the ones which are, are usually advertised on sites like Flight Global jobs, Aeroprofessionals and the likes.
Good luck!