Setting is generic fantasy. I'll probably just use bits of our existing forum setting because I'm lazy but no prior knowledge would be necessary.
To make a character, choose a class from bard, cleric, druid, fighter, paladin, ranger, thief, wizard, barbarian.
The game rules don't allow two of the same class in a party so pick something someone else hasn't already called dibs on. If someone takes one you really want then play rock paper scissors for it or something.
Make a post here reserving your class and then I'll go into the character creation process more (Spoiler: There's nothing to it, you just have to make a few small choices.)
Oh, word of warning, I'm going to be sticking to the letter of the rules in the book for this first time running the game and for some reason the book limits race by class (for example bards can only be human or elven, no dorf bards) so bear that in mind.