First of all, if you want to center the title of the paper, you can press ctrl+e, so that the title of the paper can be centered.

Then ctrl+a selects all the contents of the article, and then press ctrl+] to quickly enlarge the font. ctrl+[ can quickly reduce the font.

Press ctrl+5 to adjust the line spacing to 1.5, click the ruler position in the upper left corner, and then press the left mouse button to indent the first line.