As a new DM and new to the whole pen and paper genre, I am wondering how much detailed should my world be at the beginning of a campaign.
For example, if a player wants to create a cleric, I should probably have already picked what gods exist in my world for them to choose from.
Also, considering that the PCs are supposed to have lived in the world, shouldn't they also know of any kingdoms etc. that exist in the world? Wouldn't that though defeat the whole concept of organically creating the world along the campaign as PCs adventure through it? And wouldn't it be too tiresome to detail and keep notes from the very start of all the laws and history a world has in order not to lose coherence in case a PC asks a question that could connect to the whole universe?