Adding pictures, icons, and simple shapes to a slide works almost the same way as in Word.
Insert tab → Pictures, Icons, or Shapes. Drag a corner handle to resize while keeping proportions — the same rule as Word.
Right-click → Bring to Front / Send to Back controls which object sits on top when two overlap on the same slide.
Picture Format tab → Crop shows draggable handles on the edges of an image — drag them inward to trim away part of the photo without leaving PowerPoint. Crop → Crop to Shape trims the image into a circle, star, or any other shape instead of a rectangle.