Can't pull up Fill and Stroke style dialog pop-up

I'm a new Inkscape user, but I couldn't locate a "fix" for the following problem: I'm unable to pull up the Fill and Stroke dialog box to change line width and other properties. I'm an "old-fashioned" graphic designer, now retired, who grew up in the pen-and-ink and technical pen era, so I'm slowly learning about the power of computer graphics via Inkscape, which is far, far superior to CorelDraw X5 which I had been using. I'd appreciate any suggestions about correcting the Fill and Stroke situation described above. Many thanks!