If you want to block an entire instance of Lemmy you can use the /d/ (for domain) function. For instance, if you didn't want to see anything from lemmy.ml you could go to https://kbin.social/d/lemmy.ml and click the block icon on the right side. You can manage your blocked domains from your settings. You can also block individual Magazines/Communities by going to the community and clicking on the block icon.
Also, I'm not suggesting that people should be blocking either of those domains. They were just some of the first options on my feed that I could copy for examples.
ReCursing
birlocke_