How to use short code?

I’ve read through the documentation but I’m having trouble displaying the news content on a page using the [sp_news] short code. I’m new to php and WordPress, so please excuse my ignorance.

The error message I’m getting is:
Parse error: syntax error, unexpected ‘[‘ in /home/compl73/public_html/news.php on line 72

Otherwise, if I try using the do_shortcode function I get:
Fatal error: Call to undefined function do_shortcode() in /home/compl73/public_html/news.php on line 72

Can someone please post the most rudimentary code for displaying the news content on a page?

Thank you

https://ww.wp.xz.cn/plugins/sp-news-and-widget/