Cloning your theme is required to edit your stock theme, such as personalizing the theme colors or font to name a couple. These are the steps to do so.
Navigate to Website > Theme. If you haven't done so, switch to the stock theme you'd like to edit. For this demonstration, we're using the Raise theme.
Click New custom theme.
Name your theme and leave Clone your current theme and Switch site to your new site theme immediately selected. Click Create theme. It will take around 10 minutes for cloning to complete.
When the 10 minutes have passed, return to the Theme tab by following this path: Website>Theme. This is how it will look:
That's it! You're ready to make theme edits!