I have been into the system for some months now and I have made over twenty posts but no simply merit has been given to me or earn by me and this make me to be surprise on how these merit are generated, given or earned. However, looking at it in another perspective, I don't know if it is because I did not meet the number of my post require to earn a merit or because of the low quality of my post that is the reason why I had not been able to earn a single merit. So please I will like to get more clarifications on the possible requirement for earning merit.
Just as act mentioned in the first comment, 1 posts is enough to gain merits, if the post is worth meriting and also you may make 20 posts and not received a single merit, what make posts meritable is the content of the post, and not the number of posts, I still remember when I make my first post that generated me alot of merits in the early days of my forum journey, from that single posts I earned close to 15 merits so that show that the posts gained alot of views and attention to have generated such public interest.
So before you make that post, always make sure to include all the necessary content to make it worth reading and useful too.