I am relatively new as well. Someone asked for some clarification on an edit I made, and it turned out I had made a mistake.
In addition, if you leave notes, those may go without interaction for a long time. Although it is true that notes can be resolved without any further input from the original account.
You can block an instance via any post on it:
first blocks the user who posted
second blocks the community it was posted in
third blocks the instance the community resides in