My advice is don't, at least not yet. The best third party auditors are those who have spent a while in the food industry and have experience in different food sectors. Get experience internal auditing, visit other sites if you can but leave it a few years. This forum is filled with examples of poor auditors and while inexperienced food professionals can be good auditors, experienced food professionals are always better.
Could not agree more!
I am a former SQF Auditor (switched hats a while back) and was granted 28 food sector categories/high risk that I could do audits on... that's a LOT of FSC's that come from a lot of experience in the food industry in various roles.
You want to seize the opportunities to get onto internal auditing at your company, ask to go on company audits of suppliers, see if you can shadow an auditor as well - mostly gain experience not only in food pack in board range as well that will include packaging and logistics, storage, farm, packing operations, etc.
My own run up to being an SQF, IFS, BRC and FSSC Auditor including starting out in the restaurant business at 7 years old, going on to work up the ranks to become a professional chef and leaving the business behind to do something that I always wanted to do and that was become a hotel and restaurant auditor - little did I know this would lead into first inspecting big box stores with food operations to inspecting first packaging companies, then transportation companies and finally into 3rd party food factory etc auditing and getting to be one of the first SQF Auditors in the country - funny thing was SQF was so new in the states that they were a bit dis-organized and I ended up doing my first SQF audit at a nut company in California before SQFI issuing my credentials - oh that was fun!
So, if takes a bit of a background in various things - add on top of that learning to deal with various personalities and understanding how to separate truth from outright lies.
Do all this or part of this first before you venture into being an Auditor and you'll turn out to be an excellent auditor that is sought out for assignments. The more experience you have, the more categories you qualify for = $$$ more money and a much more stable position.
Auditors that lack enough experience and lack the ability to work on their own and handle people are a dime a dozen - truly experienced ones that believe in being firm but fair are GOLD!