To answer the question in your title, there's absolutely nothing wrong with having a low helpful flag count (except if that's due to a bunch of rejected flags). If you're happy to ask and answer questions and cast the occasional close vote, that's great. Most of our best contributors do just that, and they are what make the sites work.
Helpful flags are a handy metric during moderator elections because we're electing people primarily to handle flags. If someone has shown that they understand what is and is not proper to flag, and has taken the time to do so, odds are they'll help to process the thousands of flags we get every day. That's not the entire story, of course, because we had some extremely well qualified candidates in this last election with lower helpful flag counts. People tend to fixate on raw numbers, though, which is why earlier elections were mainly based on who had the highest reputation score.
If you want to help out by flagging content that needs it, there are a few places to look. The easiest flags for us to process are the non-answers. Many people will leave behind "me too" comments or follow-on questions in answers, as well as some complete gibberish and spam. This older Meta question has some queries within it you can run to find answers that really aren't, and I still use variants of some of those to clean out problematic content. Additionally, this Meta question describes a few Data Explorer queries for finding potential spam. The Late Answers and First Post review queues are also places where a lot of spam and non-answers will pop up.
As a warning, don't just flag everything returned by one of these search queries or review queues, because that doesn't help anybody. "Not an answer" flags should be for things that can be seen as being non-answers without having to read anything else in the question. If something requires a little explanation, don't hesitate to use an "other" flag to describe what's wrong ("This is intended as a comment on Bob's answer.", for example).
I personally appreciate detailed "other" flags describing large-scale problems that we might need to act on. This could be plagiarism, obvious voting fraud, extremely rude and abusive behavior, or other exceptions that need handling.
Finally, please don't try to game the system by hitching a ride on flags in the 10k flag queue. Only add your flag to something there if you legitimately want to increase its visibility to us. We can see when people do this, just like we can see when people flag everything in the Low Quality Posts review queue as low quality. Flag because you genuinely want to help prune bad content and deal with odd issues, not to boost some arbitrary number.