Help! 15 days on Steemit

I have been to Steemit for almost 15 days. I still do not fully understand how it is attached here, however, I have all the motivation to learn.

One of the things that I do not understand a lot is, for example: my first publication had 7 days but they never paid me, what they really did was take everything that that publication had collected and remove it. Will you know what is the reason?

In the same way I would like you to give me advice or recommendations on how to get good results in a post.

I have not been a month but I would like to continue for a long time.

Thanks for your kindness.