You don't need to pay for a plan until you have the new template in the My Sites section of your Wix account. With Wix, you don't pay for your Wix account as a whole. You pay for a plan on whichever website you want to use. Paying for a plan means you will no longer see the Wix advertising banner across the top of your website. You will also be able to connect a custom domain (yourwebsite.com) and run an online store.