@Sapphire you’re in luck the amazing @Revenir created an awesome wiki with most of this information on! But beware there are loads of spoilers for the books contain in the wiki!
The current guild leaders of the guilds though are listed in the Forum Primer
There are some parts though like elements and affinities that have not been fully reveled to us yet and we only have partial knowledge of. For example weathermancy is a Weatherwatch affinity but we don’t know what it really does and can only guess. As for the elements we know that they are used in some spells such as the calling the corners spell