To import multiple Google fonts in a Webpage you can follow either one of the steps below
In HTML Page: Suppose if you want to import fonts in a HTML page..All you need to do is add multiple fonts in the stylesheet calls as shown below
<link href="https://fonts.googleapis.com/css?family=Open+Sans|Roboto" rel="stylesheet">
In CSS : Suppose if you are calling those fonts at the top of the webpage then you need to do as shown below by using a import function
@import url('https://fonts.googleapis.com/css?family=Open+Sans|Roboto|Lato');