You can absolutely do that. If you want to upgrade to a paid plan to get some of the features you want, then you can switch at any time through the My Products option in your account or with the help of a GoDaddy Guide. Once you upgrade your site will have all the same customizations and work that you've already put in place, just with the added features. See Website Builder plans and pricing for more info.
Moreover, we also recommend you pick a builder that allows you to stand out from the crowd in the long term. Besides enabling you to create a blog free, your website builder should also offer you some (or all) of the following benefits: a hosting service, e-commerce implementation, the use of SEO tools, SSL encryption, brand logo design, and the integration of other tools and programs, ranging from live chat to website analytics.