To change your template, head to the Design tab > Change Template
Preview - To see a live example of the template
Select - To select the template
After selecting the template, you will have two options:
Change Template and Keep Content - Best if you have modified the template colours and uploaded content.
Change Template and Start Again - Recommended if you would like to start all over.
To view your new template from the front end, click on website in the top left corner of the admin bar.