This site is meant for research-level questions in theoretical computer science. If it’s homework, it’s off-topic. If it can be answered by consulting a textbook, a common reference source for the topic in question, or, say, Wikipedia, it’s not research-level, and it would be a better fit for https://cs.stackexchange.com. If it’s something that cannot be answered in such a way and comes up in your research, it is on-topic. The line is of course blurry and subjective, and it’s hard to say anything more concrete without seeing your intended question.
This is a low traffic site (with only a few questions per day), and as such off topic questions of unsuitable level can make a significant portion of what you see on the home page. It takes some time for such question to accumulate the required 5 votes to close, so they often attract downvotes as well, even though I think this is wrong for otherwise fine questions that are only off-topic.
Looking at your screenshot: the “language for a NFA Automata” (10k link) question was a trivial “solve my homework for me” question showing absolutely no effort on part of the OP (and full of typos). It‘s clearly off-topic, and its low quality justifies the downvotes. It likely wouldn’t fare much better at https://cs.stackexchange.com. Meanwhile it was deleted.
The “HoTT/Univalence” question is outside my field, so I’ll just note that at this time, it has a positive score (+1) and a helpful answer, hence the downvote you have seen may have been non-representative.
I couldn’t find the “Finding the the path” question (perhaps it was also deleted meanwhile), hence I cannot comment on it either, though the title does sound homeworkish. I found it now: https://cstheory.stackexchange.com/q/50727 (10k link). This is again a homework question, hence clearly off-topic. This one does show some effort (elaborating on the OP’s approach) and is generally fine as a question (though for a different site), thus I do not think the large number of downvotes is warranted; in any case, it should have been posted at https://cs.stackexchange.com. It’s deleted now.
If you are worried whether your question will be well received, you may try to ask about it ahead here at the meta page. (This works well e.g. on mathoverflow.) However, this meta sees even less traffic than the main site, and I suspect that not many users visit it regularly (e.g., I have only seen this question by accident), thus this may not be a very effective strategy.
I would like to ask a question on this forum, on quantum computing. It seems to be perfectly on topic, according to what is declared in the help center. However, I see that many of the questions are down voted to negative values, others are marked as off-topic, but I do not understand why, not even after reading the information on the topic of the forum in the help center. I checked several times, I see often this situation.
