If you want to check whether your object/texture is ok when rendered, you may want to render that selected area instead of render your whole environment. This method called border rendering.
In order for you to do this, you need to go to camera view. and do shiftB to select the area. Then, when you rendered, you’ll notice that blender only render your selected area.
How to back to normal render? You need to select the area outside camera view. It’ll then change render area to whole environment.