Getting RSS to work

Newbie here,

I’ve been publishing my blog for about 2 weeks now, and have a small set of regular readers (hurrah!). One recently attempted to insert my site into their RSS feed reader, and it complained that there was no feed.

The RSS link on my home page produces this code when clicked from outside:

https://www.plumbbobblog.com/?feed=rss/feed/

I plug that into my browser, and get a blank page.

So, now I have some questions.

1) What would a working feed to my blog site look like?
2) It looks like the rss_url is a reference to a file in the subdirectory “rss/feed/”. Do I need to create the directory? What should the file be named (can I presume “index.html?”) and what should it contain? or have I misread this?
3) It looks like the feed from my theme gets the rss feed by a php call to bloginfo(‘rss_url’). How do I go about changing that value to produce the answer to question #1? I don’t see anything in wp_options that looks like “rss_url”, and I don’t see any config available under “Options” in my admin tree.
4) My site is hosted on a small Linux box behind a Linksys router. The IP address of the site is mapped to my domain name by dynamic DNS; the DNS reference points to the router’s IP addy, which is set to forward all traffic on port 80 to my Linux box. Will this setup interfere with rss feeds (I can’t see any reason why it would, if the feed uses the canonical domain name…)
5) If I didn’t have y’all to rely on, what book would teach me what I need to know about this?

Thanks for your expertise, folks.

Phil W.