You might use your SLR lenses as a guide, if you have some wides.
By the numbers:
Field of view
21mm -- 81 degrees wide, 60 degrees high, 92 degrees diagonal.
25mm -- 70 degrees wide, 50 degrees high, 80.5 degrees diagonal.
28mm -- 64 degrees wide, 45 degrees high, 74 degrees diagonal.
All have minimum focus distance of 3 feet / 0.9 meter in the Nikon RF mount.
Each has its own character. In SLR, I vastly preferred the extra "stretch" of the Nikkor 24/2.8 compared to a 28mm lens. When I put together a user Nikon system close to twenty years ago, the 25mm Nikkor was too scarce and valuable for my taste, so I made due with a Nikkor 28/3.5 and a Zeiss Biogon 21/45. I used the 28/3.5 about 90 percent of the time and the 21mm Biogon when I reallyl needed the extra coverage. That usually means either interiors or showing the relationship of a subject to its surroundings. Last year, I ended up buying a Cosina 25/4 to fill the long missing gap. At this point in my shooting journey, I have become so adapted to the 28/3.5 that I still carry it about three quarters of the time, and carry the CV 25/4 instead only when I think I'll need to go wider, usually when traveling.
For what it's worth, here are some kitchen table shots of the 28mm, 25mm and 21mm. The subject changed considerably for the 28mm shot, but you can use the lamp in the upper right corner to judge relative sizes of background elements and coverage.
W-Nikkor 28mm f/3.5, wide open, 3 feet focus.
Cosina Skopar 25/4, wide open, 3 feet focus
Zeiss Biogon 21/4.5, wide open, 3 feet focus