Looking at the map:
The "Great Glaciers" suggests a region in the far north. It might be the Great Glacier, a location in the continent of Faerun, north from Vaasa, Damara, and Narfel.
Altho a "sea" is normally saltwater, freshwater lakes are sometimes called "seas", such as the Sea of Galilee. Oppositely, a salt lake is also possible.
As a hypothetical location, the "Alicorn Sea" might be a local name for the Icelace Lake, northerly of Narfell. The Sea of Sorrow looks like a landlocked lake, thus is also probably freshwater. It might be a shallow wetland, thus ambiguously mapped as part of dry land or sea.
The off-map "Far West" is then NW Faerun, the Sword Coast. The "Forest at the Edge of the [Known] World" is the elven High Forest that is part of the wider forest area of NW Faerun.
The comic suggests Venger is a Wizard of Thay, and Thay is somewhat nearby, SE from the map.
The Abyss would be a name of a local phenomenon, relating to the Giantspire Mountains to the W of Narfell. Perhaps it is a rift valley, or even a sinkhole having collapsed down into the Underdark. Flame Mountains would be the name for the northern range of the Giantspire.
The "Realm" is a coloquial or formal name for this particular region that the map depicts.