I haven't actually started any RP yet since I'm getting to 60 first and getting geared for the end-game so my static doesn't put my head on a pike, but I'm looking to get started sometime next week.
My advice is to not worry about messing anything up. I know, a lot easier said than done. But! For the most part a lot of the lore on our race is open ended, so you can go about it however you like and whatever you think would make sense for you. Hell, even most of the tribes are open to a lot of interpretation. Don't look at it as something daunting or that you need to know absolutely everything (there's not a whole lot TO know, actually), but instead something that allows you the freedom to do what you want.
Another interesting note is that the Allagans were aware of Au Ra and were in contact with them in some capacity, so I honestly would find it hard to believe that the races of Eorzea would be completely ignorant of them. If anyone knows more about if this is specifically addressed in game I'd be interested to know about it, though.
My advice is to not worry about messing anything up. I know, a lot easier said than done. But! For the most part a lot of the lore on our race is open ended, so you can go about it however you like and whatever you think would make sense for you. Hell, even most of the tribes are open to a lot of interpretation. Don't look at it as something daunting or that you need to know absolutely everything (there's not a whole lot TO know, actually), but instead something that allows you the freedom to do what you want.
Another interesting note is that the Allagans were aware of Au Ra and were in contact with them in some capacity, so I honestly would find it hard to believe that the races of Eorzea would be completely ignorant of them. If anyone knows more about if this is specifically addressed in game I'd be interested to know about it, though.