Themes set the tone of your site. They can be a direct reflection of the owner: If you are a person of simple tastes you might choose a minimalist template, while larger personalities might prefer something with strong colors. You should always keep in mind, however, that a website should meet the level of professionalism of the content it hosts. You might want to think twice about using Comic Sans on a medical professional site, for example.
After you've built a site on Webflow, you will need to transfer it to a content management system. There are some features, like drag-and-drop widgets for adding social components, maps, and videos, that don't require coding knowledge. But if you want the full benefits of Webflow, you'll need to know HTML or CSS. There's a limited set of themes, a responsive interface, and your Webflow site can be customized for desktop, tablets, or smartphones.
These services can host your content on their servers free of charge, but in exchange for that zero cost, your online destination will have a less-than-elegant domain, such as jeffreylwilson.tumblr.com. That might be fine for a personal blog, but it will look too low-rent for a business that wants people to trust it enough to pay for whatever it's selling.