What you might be considering to be a fancy website doesn't have to be expensive, or complicated. My company created a software product that helps you build and sell your online course. It provides a website you can customize without a developer, a complete online school platform that you can brand with your own logo, and built in payment processing so that new students can signup and pay you right through your website. Our platform is much more in depth than a simple website with videos of your content. We've studied and carefully optimized our platform to help guide students through your course. You'll also have analytics so you can measure student performance yourself. All of this is $49/month including hosting for your site.
That said, whether you end up using course creation software like ours or not, the site or software itself isn't going to get you new customers. You will still have to do the same work in promoting your courses regardless of how fancy or expensive your website is. If you haven't been selling or building an audience online, then you should start building up your online presence, even if you don't have an online course website built yet. The best way to do this is to start creating great content. We recommend starting with the avenue that is most comfortable to you (maybe that is writing, maybe it is recording videos). You can start publishing content on social media, on a blog (you can setup a medium.com account if you don't have a website), and on sites like youtube. If your online course hasn't been setup yet, what you will want to do as a minimum, is to start collecting email addresses. You can use a tool like Mailchimp, or ConvertKit to do this and to create email newsletters. This way when you are ready to launch your online course website, you will already have a group of email subscribers to promote your launch to.
Finally, don't get discouraged if you don't get a response after creating your first few pieces of content. It takes time and a large volume of quality content before you may start getting noticed. Think of other successful content creators who you've followed before online (even if they weren't specifically course creators). They likely put out a significant volume of content, and when they first started online they were likely in a similar position as yourself.
There much more that could be said about creating an online course business than I can fit in an answer here. If you'd like to read more, we write on our blog to help our audience of course creators learn how to build and promote their online course: https://www.heightsplatform.com/blog