The above two posts, although contradictory, are mostly true. I know that doesn't really answer your question, but there are a lot of variables. I have seen new hires be awarded FLL right from initial training. LGB (our other base at this time other than JFK & FLL) is a little tougher to get because of the semi-limited flying out of there due to the slot constraints. If you have been keeping up with the news, BOS will be our new "focus" city so that has great possibilites of becoming as big as our JFK operation over the next few years.
We have a plan for "virtual basing" in the works and it could come to be in the next few months or sooner, who knows. It's a great idea for our QOL and would save the company a chunk of coin at the same time. If you live in, or close to one of our bigger Blue Cities (MCO and BOS come to mind) you could find yourself starting/ending your trips from there even if there is no formal base there. Time will tell on that one but it has great potential.
Good luck