There are a few different ways that you can zoom in and out on InDesign. One way is to use the View menu. Go to View > Zoom In or View > Zoom Out. You can also use the keyboard shortcuts Ctrl++ (Cmd++) to zoom in or Ctrl+- (Cmd+-) to zoom out.
Another way to zoom in and out is to use the Hand tool. Click and hold down the Hand tool, then drag up or down to zoom in or out. You can also use the mousewheel to zoom in and out.
Finally, you can use the Zoom tool. Select the Zoom tool from the Tools panel, then click and drag to zoom in or out.
If you want to quickly zoom to 100%, you can use the keyboard shortcut Ctrl+Alt+0 (Cmd+Opt+0 on a Mac).