If your PHP code is being displayed in the browser, it means that your
server has not been setup to serve PHP scripts.
You can use something like XAMPP. If you do, activate 'Apache' and 'MySQL'
After you do that, go into the download directory and go into 'htdocs'
(default: 'C:xampphtdocs')
Make a folder with your PHP code in it.
To access the website, go into your browser and type:
localhost/FOLDER_NAME_WITH_PHP_HERE
NOTE:
this will only allow you to view it locally, nobody else will be able
to see the website.