John Mueller of Google explains how to utilize different schema markup types on a single page. You must stick to certain dos and don’ts in order to accomplish the desired results.
A discussion on this topic took place during the Google Search Central SEO hangout. There was a question from a site owner about what to do with a page that is both an FAQ and a how-to, as well as an article.
If you use multiple structured data markups on one page, there are two things to consider. Google’s guidelines are the first thing to follow. A schema needs to match the primary elements on the page with their schema properties.
Another aspect to consider is the fact that Google’s rich results only support certain types of structured data.
The markup is the best way to make sure you show a specific rich result. When it comes to earning an FAQ-rich result, it is best to leave out how-to markup. It is fine to provide a specific kind of structured data if your site requires it.