> Is there a way to connect (preferable with the ability to post) with it for free?
Yep, you can get a free account at https://www.eternal-september.org/ if your ISP doesn't carry newsgroups (note it's for text groups only). Personally, I use Thunderbird as a newsreader (and my ISP still carries most newsgroups), there are also dedicated apps like Pan: http://pan.rebelbase.com/
Does gnus still work? Is there a way to connect (preferable with the ability to post) with it for free?
How does one make a newsgroup?