Welcome! Don't be too comfortable on your poser background, Bryce is a whole different beast to tame. As far as the other things, there's the Skylab (Which you can access in the upper-right of your screen, there should be a small cloud and sun/moon icon there) which allows you to create Bryce skies, and there are ways to bring in photos using 2D planes. And for importing poser characters into bryce, use the search function of the forum. That question has been asked roughly 1,932 times. So...have fun, and don't walk on the grass.