Welcome on steemit, don't worry about what to post, just think what you are best at and enjoy most, which some already in your plan. Beside, it is not always about posting, comment other community member post and of course if you like it, give your upvote, is also consider as already beeing active in the community. In the platform you will find many other stuffs that you will find interesting and eventually become a way to get something to post, for instance utopian-io platform that link with steemit. There are many project that you could get involved with and share it to steemit. And many other thing that you'll figure it out along the way. So again, welcome on steemit, you definitely going to love it.