If you're looking to incorporate new fonts into your website, the best method is to use HTML in the header with these lines:
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=Kalam:wght@300;400;700&display=swap" rel="stylesheet">
Then, in your CSS, you can specify the font-family like this:
font-family: 'Kalam', cursive;
Alternatively, you can import the font directly into your CSS using this method:
@import url('https://fonts.googleapis.com/css2?family=Kalam:wght@300;400;700&display=swap');
If you have the font downloaded on your computer, you can also use this technique:
@font-face{font-family: fontName; src: url('../fontURL');}
Remember to replace "fontNAme" with your font's name and "fontURL" with its file URL.
I highly recommend sticking to good practices by utilizing web-based fonts, such as those from Google Fonts, and importing them through your HTML.