OK here is another question.
With the stock and really limited assets that come with DAZ the included scenes don't have extended sky or some sort of background, and if you go to far to one side or the other or back away there is black areas to the sides with no apparent fill in for sky etc; Is there a way to fix this? I am looking for different scenes to add to the library, but not finding a lot to my liking

so far. The library is another question coming right up.....
So the two sample images you attached actually are two different scenarios:
1. the beach
This is a specific backdrop prop that is only designed to have renders looking basically directly perpendicular to the backdrop. If you rotate the camera view on the z-axis to the sides a little you'll see the shadows cast by those rocky protrusions, and further to the side you'll see the edge of the prop.
There are actually very few backdrops like this for daz, it does not seem to be very popular.
2. The pool
This is an architecture prop which only contains foreground and middleground elements. So there is nothing to reflect light into the virtual camera lens so it just looks black. (note that you can adjust the color of the nothingness)
You've got two and a half choices:
a) use a HDRI.
This projects a special type of image called a HDRI onto the inside of an infinite dome centered on the camera.
HDRI textures are different from regular raster images because they map to a full 360 sphere (normally with some distortion and loss of resolution at the north and south poles), and they generally have their brightness scaled very non-linearly.
In this case the HDRI image becomes a light producer with all "ray" of light going directly toward the camera virtual lens.
There's a lot of HDRIs available specifically from Daz vendors, and also you can theoretically use HDRIs from any other source too. The HDRI packs specifically for Daz often have one-click setup that assign everything to your render->environment settings for you.
To do this manually add a "HDRI" texture map to the render settings (Render Pane -> Environment. Enable draw dome. Set the chosen HDRI in the Environment Map image, adjust the intensity etc as desired. Use the dome orientation and rotation settings to move the dome image around to get the specific background angle you want.)
b) fill the middle and far background with other architecture props so there is no line of sight to the horizon or the sky. This works better for indoor scenes obviously. Note you will still need to put something outside and windows, doors or openings.
c) (This is the "half" because it's not a common or easy solution) place primitive plane objects behind the architecture and apply "normal" images as the Diffuse texture of the standard material. This only works if the normal image has nearly exactly the correct angle/height/focus etc to match the position and direction of view of the virtual camera. You can fudge it a bit by setting your virtual camera to have Field Of View enabled and adjust the focal settings so the far away objects are blurry.