Like many of the features of Google Workspace, there are many ways to customize Google Docs to ensure that your document looks just the way you want it to.
To change margins, page color, and orientation, click File > Page setup.
Use the toolbar to customize your document further. Here are some highlights:
Undo or redo 
your last changes.
Use the paint roller 
to copy formatting from one section of text and apply it to another section.
Zoom 
.
Assign styles for headings and titles 
.
Change font and font size 
.
Add bold or italics, underline, or change the font color 
.
Insert a link 
for selected text.
Insert a comment 
.
Choose text alignment 
.
Choose line spacing, bulleted and numbered lists, indents, background colors, and other tools 
.
