If you have members of your target marketing following you on social media, publish a post where you ask them to reveal any specific questions or challenges they have about your course topic. Just like with an email, you could share a link to a survey as an alternative to responding to you publicly (this might be the better option depending on the nature of your course topic).
As far as actually doing the nuts and bolts building and design of your site, you also have plenty of options. You can hire someone to design and code a website, or you can try your own hand (if you're a novice, The Best Courses for Learning How to Build Websites is an excellent starting point). You can use an online service to create web pages, or build it offline using a desktop software tool. Or, if you're a coding dynamo, use a plain text editor to create a site from scratch. How you mix and match these decisions depends on your skills, time, budget, and gumption.
One thing to remember with marketing: results aren’t always immediate. To more effectively promote your new website, you’ll need a combination of marketing techniques, such as SEO, social media marketing, pay-per-click ads, retargeting, answering forum questions that are related to your niche, or creating content for more popular websites in your industry via guest blogging.
A sales funnel only works if people actually enter the sales funnel. To get those people, you either need an audience (your email list, blog readers, podcast listeners, social media followers, etc.), or a willingness to hustle and/or spend money on ads to get people into the funnel. Until you get people into your sales funnel, it won’t convert anyone.
The Ultimate ECOMMERCE Sales Funnel (Hacking The Growth Curve)