PCs can be of any class found in the Pathfinder Core Rulebook. Native (non-Bright) humans may play a pionic or psychic warrior, native trollkin may play a shaman, and native half-elves and half-orcs may play warlocks. These four racial classes are of the 3.5 variant.
An important note; warlocks and shamans are much different in 3.5 than in 4E
To gain new spells, wizards must copy spells from other wizards, seek out archived spells in city libraries (if they have any at all) or make bargains with the Travelers. Otherwise they must rely on their meager spell gains that occur alongside level ups.