Do you want to upload a template/theme in Joomla? Well, it is very easy and quick with TemplateToaster. You can follow these steps to upload your theme/template in Joomla:
STEP 1: Log in to your Control Panel.
STEP 2: From the top navigation bar of panel, navigate to Extensions -> Extension Manager.
STEP 3: Click the browse button and install the theme by clicking on the upload and install button.
STEP 4: After uploading the theme, set the theme as your default theme.
STEP 5: Now you can visit the site and can see how it looks on the browser.