>>7
if you're using some page generation or blog software on your site, it should have an option to make a feed and you might already have a feed.xml or atom.xml being put onto the site
otherwise, you'll need to do it by hand

here are the more technical bits if you are going to do it by hand (this is Atom, a slightly newer, simpler format that just about every reader supports)
http://www.atomenabled.org/developers/syndication/

and here is a template for making feeds and feed entries - save the result to atom.xml on your site and link it
https://miredo.neocities.org/meeat/meeat

and this is a feed made using that template as an example
it has some comments on it that might help
https://miredo.neocities.org/atom.xml

>>7
here's a good post about that:
https://everest-pipkin.com/teaching/handmadeRSS