how do you get rich snippets?

Structured data. You add schema markup (JSON-LD is the easiest form) describing what's on the page - product with price and reviews, recipe, event, article and so on - then run the URL through Google's Rich Results Test to see if it's picked up. The catch people miss: valid markup only makes you eligible, it doesn't guarantee anything. Google decides per query whether to show it. And some types have been cut back hard - FAQ results are basically limited to government and health sites now, and HowTo results were dropped - so check a type is still shown before spending time on it.