Modules allow you to display certain elements on your site in key areas around the template. Modules include things such as upcoming events, latest news, polls, latest items added to store and other things.
Steps on how to install new module on your joomla website:
Step 1: Look for a site that has a module you to be downloaded or look the picture below for example
Step 2: Choose a module you want to be downloaded
Step 3: In order the module to be downloaded, click download button
Step 4: Check if the downloaded file is already done
Step 5: Go to your Joomla Administrator
Step 6: Go to Extensions and Click Extension Manager
Step 7: Choose the downloaded file to the Extension package file
You will see a message like on the picture below if it is successfully installed
Step 8: Now, you can check the newly installed module.. Go to your Extensions and click Module Manager
Step 9: Now, if you want to activate the module. Go to site module and click the Disk icon
Now we are done in setting up a new module