First of all, if you read the message you got again, you will notice that no-one has been banned for anything there. It is simply a little heads-up to take a little more care when asking future questions.
Now, why did you get this message? Since you ask, no, it's not just 2 questions and it's not just 3 downvotes. To be precise, you asked 10 questions on the main site so far:
- 60% of your questions have a negative score
- 60% of your questions have been closed, and
- 40% of your questions have been deleted
(those sets do overlap, and are sure correlated).
This is a pattern that's at least a little alarming and if anything, shows that you might be struggling a little with asking questions. Is this reason for moderators to ban you? Probably not, but it's worth a notice to maybe remind you of working on your questions and understanding of the site a little more.
However, I notice that you (more or less) coincidentally also triggered an automatic question ban. However this is not moderator-initiated rather than automatically and is not directly related to the message (although, ultimately for pretty much the same reasons). But it also shows that you haven't actually encountered that block yet, so this can't be what you're asking about here. To learn to get rid of that automatic question ban, you can take a look at this guide, which presents the same general advice as the moderator message you got.