If you plan on using the RSS Feed widget that comes with WordPress, and you would prefer the RSS Feed links to open a new page or tab rather than take your visitors away from your site, you will need to follow these instructions.
You’ll need access to your web host’s file manager or FTP access. Once logged into either, navigate to your website’s home directory, then go into wp-includes and look for widgets.php. Once that file is open hit ctrl + f on your keyboard and search for href=’$link’ and replace it with href=’$link’ target=’_blank’. You should see 2 instances, replace them both and save. Now your WordPress RSS Feed widget links will open a new tab or page.