Somebody else in this thread linked a Github repo listing “Awesome RSS Feeds”, they have categories by country and by topic.

Otherwise, this is the method I use to find RSS feeds from websites that don’t have a link/button to their feed (copy/pasted from my other comment in this thread):

You can often find RSS feeds by checking the page’s source (on Firefox: right-click and “View Page Source”) and using Ctrl+F to search, there’s usually a URL somewhere. Keywords to search for: “feed”, “RSS”, “xml”, “atom”. For example, if I go to this community’s page on lemmy.world, I can Ctrl+F “feed” on the page source to find lemmy.world/feeds/c/technology.xml