You could begin by taking a look at this.
https://swedenborg.com/emanuel-swedenborg/explore/spiritual-world/
one text that is a good starting point is this:
"Life in the World Unseen"
You can buy the published book, but it';s copyright has expired, so you can also download a pdf version.
http://www.innerpath.com.au/borgia/AnthonyBorgia-Life%20In%20The%20World%20Unseen.pdf
One thing you must keep in mind, however, is that because the spiritual world is a realm where subjective nature affects perception. Thus, there are often many varying interpretations about the spirit world, and for the most part, everyone is dealing with an incomplete set of understanding. Some understand <this> aspect more, some understand <that> aspect more.
So the investigation and study or learning in this area should always go hand in hand with a practice of prayer and offering the work to God, and always asking for God's guidance (through the Holy Spirit, for example). This should be augmented by reading the scriptures, although one should also be aware that 2 thousand years of theology still hasn't been able to break through on this level, or come to an accurate grasp of the spiritual reality behind the gospels, (imo).
In other words, read scripture, but treat any theological position as you would any other teaching: always offer it to God and ask God to show you to what extent that theology is valid. It's always a mixed bag (imo).
You could begin by taking a look at this.
https://swedenborg.com/emanuel-swedenborg/explore/spiritual-world/
One thing you must keep in mind, however, is that because the spiritual world is a realm where subjective nature affects perception. Thus, there are often many varying interpretations about the spirit world, and for the most part, everyone is dealing with an incomplete set of understanding. Some understand <this> aspect more, some understand <that> aspect more.
So the investigation and study or learning in this area should always go hand in hand with a practice of prayer and offering the work to God, and always asking for God's guidance (through the Holy Spirit, for example). This should be augmented by reading the scriptures, although one should also be aware that 2 thousand years of theology still hasn't been able to break through on this level, or come to an accurate grasp of the spiritual reality behind the gospels, (imo).
In other words, read scripture, but treat any theological position as you would any other teaching: always offer it to God and ask God to show you to what extent that theology is valid. It's always a mixed bag (imo).