WordPress Theme Permissions
You can upload new themes to WordPress or use the basic themes installed by default. If your permissions do not give you access to the theme uploader, contact your network or site administrator for assistance.
Uploading a New Theme
To upload a theme on a new site, hover over over Appearance in the dashboard and click Themes.
From the Theme screen, click Add New.
At the top of the screen, click Upload Theme.
Use the desktop browser to locate the zipped theme file you want to upload and click open.
Once the file is selected, click Install Now.
When the theme is finished unpacking the “Live Preview link” will take you to the customizer for a preview, customizations and activation, or click Activate to make your new theme live on your site.
Choosing Between Multiple Themes (Default WP Themes and Manually Uploaded Themes)
The Add New Themes page lets you search through and preview thousands of themes before installing them. Hovering over a theme will reveal install, preview, and detail options.