Choose Pages > Settings (from the Pages menu at the top of your screen), click Rulers, then select the checkbox next to “Show vertical ruler whenever rulers are shown.”
Move the pointer over the vertical or horizontal ruler, click, then drag the guide to the page.
Note: If text is selected, click somewhere else to deselect the text before clicking the ruler.
To change the location of an alignment guide, drag it.
Some page templates have persistent alignment guides. To show or hide these guides on document pages, choose View > Guides > Show Page Template Guides or Hide Page Template Guides (from the View menu at the top of your screen).
Do any of the following:
Remove a horizontal guide: Drag it up and off the page.
Remove a vertical guide: Drag to the left and off the page.
Hide all guides: Choose View > Guides > Hide Guides (from the View menu at the top of your screen, not the View button in the toolbar).
To show all guides again, choose View > Guides > Show Guides.
Hide all page template guides: Choose View > Guides > Hide Page Template Guides.
Clear all guides: Choose View > Guides > Clear All Guides on Page.
Choose Pages > Settings (from the Pages menu at the top of your screen), then click Rulers.
Click the color well next to Alignment Guides, then choose a color.
Tip: You can Layer, group, and lock objects in Pages on Mac