I’m not sure if I can post here. Lemmy seems kind of complicated. For instance, I tried to post something and it said I can’t because I’m on a local instance. So how do I find out what instance a community is on and how do I make it so I can post?
An example: I went to https://join-lemmy.org/instances and searched for nostupidqestions and nothing was found.
To summarize what others have said: You did manage to post. However, a moderator removed it, because you broke rule #1 of the community you posted to (which is that a post in !nostupidquestions@lemmy.world must contain a question).
The part of the message mentioning local user is that lemmy.world users get automatically notified when their posts on lemmy.world are removed. It has nothing to do with the reason your post disappeared. The usual behaviour is that you don’t get informed when a moderator locks or removes your post, it just happens silently.
Don’t feel bad about it, you’re just learning. For better chances of success, make sure to read the community rules in the sidebar before posting.
On desktop web, the sidebar with rules is on the right. On mobile web, click the sidebar button: