Since Joomla has RSS Feed integrated in it, you just need to enable and configure it.
From your Joomla administration area go to Components- > Syndicate
Now in the syndicate settings change Title and Description, Image, and select which rss formats do you want to enable. Then save your settings
Next in order to be able to see RSS feed on your website, you need to enable it.
From Modules, find Syndication module and select module position and click Yes on publish radio button. Then select on which pages do you want the RSS feed to appear. Scroll down to Parameters and choose which RSS formats that you want. Now save your settings.