Prior knowledge is not required.
I wouldn't fret.

However, if you do wanna go in armed with knowledge I find that gamerescape has good info on each dungeon (link provided for Brayflox, and the rest of the dungeons can be found in a footer at the bottom of the page).
Hopefully this helps, and either way glhf
https://ffxiv.gamerescape.com/wiki/B...x%27s_Longstop