(Please start new threads for new issues — your question is totally different. I've moved this to a new thread.)

Did you have feeds previously on this computer? Did you delete them?

You can add new feeds from File → New Library → New Feed.

I don't know if you expected Zotero to be a substitute for a conventional feed reader (I don't think the feature was intended for that) but many people find Zotero's RSS utility to be extraordinarily useful. I'm responsible for an online bibliographic service that monitors the contents of many scientific journals. We add articles that are relevant to safety and assign the articles to any of several categories or topics. Each topic has a RSS feed. One of the topics is drowning occurrence, risk factors, and prevention. I know of more than 50 subscribers to my drowning feed who use Zotero -- many of these began to use Zotero (as opposed to other bibliography management software) because of the RSS feature. There are probably an even greater number but personally I know of these who are members of California, and world drowning research groups. My feed consolidates new articles about drowning from umpteen journals arising from many professional disciplines.

I, myself, use the Zotero feed utility because it saves me the effort of regularly checking journal websites for new articles. Initially, I found the process of capturing and importing articles into a collection a bit tedious but, now that I'm accustomed, I think it is simple and natural.

Maybe if you say what you were expecting, someone here could help. I know that in most of the world sliced-bread isn't a particularly valued commodity but the "better than sliced bread" is a meaningful comment about Zotero RSS here in the USA.