How to grow a company organically?

Context: I've built and just launched a subscription based paid service that aims to help people do well in their analytics/machine learning job interviews. Idea is that subscribers will receive highly curated interview questions and answers regularly. (Not trying to astroturf but PM me if you are interested.)

Question: How do I grow the company organically? Do I prioritise content generation? Which kind of content generation is the best? Blog posts? Social media?

Other details: This is a one man team. I handled subscription content generation, backend (using AWS serverless architecture), website (using wp). I don't have intention to hire anyone full time. Open to using freelancers.