Hey mariana!
Great to see you have decided to join steemit.
If you'd like to know how to use the platform more I'd recommend you check out @allasyummyfood's video tutorial posts.
Here is one for example:
https://steemit.com/steemit/@allasyummyfood/2-video-tutorial-how-to-write-a-post-on-steemit
You may have to scroll down in her feed a little but you will find some handy tips and tricks on how you can tackle the site.