From an SEO standpoint, there is nothing wrong with categories ranking. Quite the opposite, many people want categories to rank. It allows users to find entire categories instead of single pages, and puts more entries from the website into the index. (Tags, however, should generally not be indexed.)
In your case, Google sees the category as more relevant to the search query than the single page. There are many potential reasons for this. Maybe there are more backlinks to the category pages from somewhere relevant. Or maybe it has something to do with your website structure or meta tags.
What's going on below this first result? Is the article in the index? Is it ranking? Are any of the articles ranking? If not, you might have a technical issue on your site somewhere.
You could noindex the category pages if that's relevant to your strategy. But keep in mind, this can have an adverse effect, if your category pages drop out of the index and your single pages still don't rank.
Furthermore, if your category pages look like spam, you can improve their appearance in search before noindexing. Update your title and description tags, include a good feature image, update your copy.
Here are the steps you can take:
- Do a site audit. Is your SEO plugin optimized? Is your site structure sound? Are the meta tags the right/intended ones?
- Check who links to your site, and to which pages.
- Check if your blog post pages are even ranking, and where.
- Improve the appearance (in search results, at least) of your category pages.
- If all else fails, and there aren't any serious backlinks to category pages, sure, experiment a little, and if you don't get the results you want, reverse the changes. (Just make sure you're only noindexing but still letting the crawlers follow the links to and from these category pages.)