First of all, unless you get lucky with manaburn parties, you won't be able to get a party at all on BLM. These days, BLMs have been cast aside in favor of meleeburn set-ups at almost all levels, but especially 55+ since nobody wants to do anything except colibri parties. That's something to consider.

Honestly, it's a pretty awful time to start playing FFXI unless you already have a lot of friends playing the game. While it's certainly taken a turn away from punishing anyone for playing casually, it's still a stretch to say that FFXI is by any means casual-friendly. Not sure how that affects you as I don't know your play style.

At this point, I suggest waiting for FFXIV.