Before you can decide which position to assign a module to, you need to know which positions your template has available, as each template can define different positions at different locations on the page. In this tutorial, we’ll show you how to view the module positions in a Joomla 3 template.
View Module Positions in Joomla 3
Step 1. Navigate to Extensions => Templates
Step 2. Click on Templates in the left menu.
Step 3. Click Options button on the top right side of the page.

Step 4. Select Enabled for Preview Module Positions and then click Save. Enable the preview of the module positions in the template by appending tp=1 to the web address. Also enables the Preview button in the list of templates. Please refresh the page after changing this setting.

Step 5. Repeat Step 1 and Step 2.
Step 6. Click on Preview link.

Now you can see all available module positions.
