The above mentioned tools are found on the View Ribbon in the Show Group. In the image you see here I’ve checked off all three items to be shown. The Ruler is visible in the gray area at the top and on the left. The Gridlines form the small squares you see and the darker vertical and horizontal center lines are the Guides. To center the lion image all I really needed were the Guides. However, if I were adding more images or objects the Gridlines would be very helpful in positioning them.
Though I find the Guides and Gridlines very helpful, I also find them distracting, so when I’m not using them I simply uncheck their boxes and they go away. When I need them again I know where to find them.
Next time I’ll tell you how to make it look like you have both portrait and landscape oriented slides in the same presentation.
If there’s something you want to know how to do in PowerPoint, let me know and I’ll see what I can do.