Because magic was frankly ignored in the previous setting, magic in the new setting will simply follow the standard book approach. The only difference is that there are no prerequisites (which is typical for most magical settings I run).
Magic is rare. Aside from whatever magic the PC’s brought with them (spells or items), magic is not often to be encountered. This is partly due to the low frequency of people being born with magery, but mostly because the ruling class (vampires) actively hunt any use of magic, as that is the biggest threat they face. Any real mages will most likely be either part of the resistance or in hiding.