Do blog posts increase rank of home page?

I understand that pages are ranked individually and don't gain authority from the domain. I also hear content is kind and writing blog posts with engaging content is key for ranking a site. If blog posts are on their own page, then how do they help a site rank?

I'm a small business owner, not an SEO expert, but I've been working hard to learn SEO to rank my e-commerce business. I'm working on adding content, and trying to decide where to prioritize.