this happens when you're manually putting a space between paragraphs (pressing enter twice) rather than using built-in word processor settings. on gdocs you can use find & replace and input \n(?=\n), leave replace blank, and select "use regular expressions" (1/3, word trick next)

you can just keep doing this method if you want! but if you don't want to do this every time, allow your word processor to automatically add space between paragraphs. it'll be somewhere in line spacing settings. if you can't find, you can easily look it up! (3/3)