The downvote button starts appearing when a user has 500 karma points, the threshold changes over the years, it might be 200 or 1000 now.
Your account is 10 days old and I see one comment downvoted and another might have been in the past but somebody else upvoted in the meantime and I'd say you'll be fine. Good quality, adds value, welcome to Hackernews!.
My question, which I can't ask as an "Ask HN" is that there seems to be some flag on my account that prevents me from doing an "Ask HN"...