Firstly I would say not to look at steemit as the way to make money. People are using other social media such as Facebook, Twitter or Instagram for no monetary incentive. Nobody would have even thought that you will be able to make certain incentive from making posts on social media not such a long time ago so this should really be just a cherry on the top of the cake. The whole idea is brilliant and we should look at it that way. In regards to your qestion of what to post, it is really what makes you happy posting. It has to be something of your interest so the posts come natural. At the same time you can get engaged in commenting on other people's posts to get more involved in the community and build up your following. Hope this helps. Wishing you a great day and lots of luck.