Don't know where to find the RSS feed URL of a website

You should be able to find the RSS feed by adding /feed at the end of the URL:
www.your-domain.com/feed

Usually, the RSS feed logo, or a subscribe button (which redirects to the RSS feed) are placed somewhere on the website (at the very top or the very bottom). Once you click on them, you should be redirected to the RSS feed.

Here is how the RSS feed logo looks like:

You should be able to find the RSS feed by adding /feeds/ in the URL:
http://www.your-domain.com/feeds/posts/default

You should be able to find the RSS feed by adding /feed.xml at the end of the URL:
http://your-domain.com/feed.xml

You should be able to find the RSS feed by adding /rss at the end of the URL:
http://your-domain.com/rss

To find RSS feed URL of the desired home page or blog, see this video.

You should be able to find the RSS feed by adding .atom at the end of the URL:
http://store.myshopify.com/blogs/blogname.atom

If you are using a built-in domain:
http://sitename.squarespace.com/pageslug?format=rss

If you are using a custom domain:
http://yourdomain.com/pageslug?format=rss

If you are using a built-in domain:
http://exampleblogname.tumblr.com/rss

If you are using a custom domain:
http://www.exampleblogname.com/rss

There are several types of RSS feeds you may find and subscribe to, on Medium:

User profile

To access a user's feed, add /feed/ before their username:
medium.com/feed/@Medium

Publications

For a Medium publication's RSS feed, add /feed/ before the publication's name:
medium.com/feed/the-story

Custom domains

For a  publication on a custom domain, add /feed to the end of the URL:
https://journal.thriveglobal.com/feed.

Tagged pages in publications

For a feed from a Medium publication's tagged page, add /feed/ before the publication's name: https://medium.com/feed/invironment/tagged/food

You should be able to find the RSS feed by adding /rss.xml at the end of the URL:
www.yourdomain.com/rss.xml

RSS feeds in Joomla are difficult to guess and the best course of action would be is to contact a person from the website itself and ask them to send it.

Generally speaking, Joomla RSS feeds look like in the examples below:

http://your_joomla_url/index.php?option=com_content&view=category&id=14&Itemid=473&format=feed&type=rss (for RSS)

http://your_joomla_url/index.php?option=com_content&view=category&id=14&Itemid=473&format=feed&type=atom (for ATOM)

You should be able to find the RSS feed by adding /rss at the end of the URL:
www.yourdomain.com/rss

If adding /rss.xml or just /rss after the website URL didn't help, I advise you to contact the website owner or customer support and ask them to provide you with an RSS feed.

There are ways to find which platform is being used, as there are "footprints" (evidence, clues) left behind by the platform. One way to find which platform you are using is through the view page source option.

You may access this option if you right-click anywhere on the website and select View page source, however, since there are many data available there, you might want to ask a friend who knows what and where to look for.