Hola to Steemit! I guess my advice - since I'm pretty new here myself - is to just share things that interest YOU. Who YOU are? What moves your heart and mind to communicate to a public audience. I suppose if all you really wanted to do was make money (or Steem in this case), then you can check the topics list and see where most people go. (Photography appears to be the most followed.) But if you want to be yourself here, then just say and post what makes YOU comfortable!

Since you are a doctor in Venezuela, I'm sure you have many things and experiences you could share that will bring you many followers. Already you've caught my interest (having lived in Columbia and Chile for a number of years!) Good luck @joha09sohi!