The idea of multiple planes is foreign within this setting. It is known that reality can be warped or bubbled. Magic or divine influence can create pocket dimensions or even demiplanes, but those exist still within the world, just in a spot where space is warped.
Because there is only one plane, there is no particular place where souls go when one dies. In fact, they kind of just float around until they are reincarnated. If one is not careful, souls can easily become undead. This problem is particularly true for those who died violently or with unfinished business. A proper burial prevents this, either by putting the soul into a peaceful spiritual sleep until it is reincarnated, or by putting the soul to use until they are ultimately reincarnated. Church clerics entomb the souls of respected holy persons into new churches to consecrate them, and Vananran druids invite souls into natural formations to create protector spirits. Bad and mean people use this to do bad and mean things also. Seances and divination often invoice communion with spirits that linger nearby. Certain magics involve invoking souls (usually willing and friendly souls) to assist one.
There is an trend by charlatans and con artists do perform fake divinations and seances. Now endemic in city streets and urbane parlors, this whole trend and the many high profile frauds which have come alongside it has caused many to doubt the prevalence of spirits and such. This mixed with the fact that the church usually does a pretty good job at properly burying souls have led to a time where the why behind many rituals and norms have become forgotten, leading to increased transgressions. Those who truly do interact with spirits must struggle to separate themselves from the common charlatan, and face scrutiny in public.
Souls have types and that sure may be important maybe.