Ublock will let you block just about anything, for instance if you're seeing too many posts from a specific instance ex: @leddit.danmark.party, this filter will block the entire instance
lemmy.world##.post-listing:has-text(@leddit.danmark.party)
If you click the 3 vertical dots, it should expand to reveal a star-icon option that'll allow you to save the comment. To view saved comments, click on your username in the upper right, then profile. There should be a 'Saved' tab
One other helpful snippet that'll let you filter out posts that link to wsj, twitter, youtube, etc...
lemmy.world##a[href*="wsj.com"]
I'm no ublock expert, but I've mostly tested these filters, so ymmv. If you run into any issues or need to tweak a filter please follow up so we can all share 😀