That is fine and it is what a forum is about. Few months down the track you will be helping others as all this will be fresh in your memory.
When you put the dome there think of it as it was once sunny outside but you just closed the blinds.
First few IRay renders I pretty much left it as standard and got good starting point and reasonable result by leaving things be. Then on the third render get a little adventurous. You can always click cancel render and once it stops close render window and go back and adjust back or forwards depending on what you had done. I just set up my scene and chose the Dome and Scene in Render Setting Panel (Covered bellow) I did not play with much
if you remove the skydome and any lights it had with it and revert back to just the Iray system you will be set. All you should be left with is the default camera and the content you added to make your scene. If you see things like point light and distant light chances are they were added same time as your dome if any were added at all. Lights are fine to add but might be overkill on your set as not really added by you as an improvement more to work in conjunction with the Daz dome.
You can remove the stuff you want by selecting them in your scene panel (tab) Highlight yellow right click and choose delete. You can hold control and select more than one object too
I assume you have the image the dimensions you want.
So in your Render Setting Panel(Tab) Under Environment Setting you will see the option to use Dome and Scene(Good start point this) and Infinite Sphere(leave it too) you have various tweaks you can make but get feel for it first. Then started with the sundial onto a few characters etc
Your computer has reasonable specs so it would not be long before you get a general idea of what you are going to get. I set it up then hit render within few minutes even though bit grainy if a face or prop or something is washed out I know I carried away with those tweaks. Stop Render Close Adjust and start again.

- Johnny G

"Try animation to get things moving"

lpr001@renderosity.com