Once you select a "web site type", (listed under the "Pages" tab) either Personal page or Business, you should stick with it!
If you try changing your "Web site type", after you have saved and/or published your website, you will lose the specific page names you have already done. The two types of websites, Personal and Business, have different page names with each plan.
Instead of changing the "Web site type", you can change/edit the names of your pages, or add/delete pages to the plan you originally choose. This can be done under the "Pages" tab. This way you won't have to start over from scratch.
The only difference between the website types, are the default page names and how they are set up. If you need to change the names of your pages or add/delete pages, then simply do it under the Pages tab, but DO NOT change the Web site type.