I would say write mostly in English because most people on Steemit do, even when they are from another country. Maybe after your title, put a Portuguese word in parentheses. This way if there are those who speak Portuguese as well, will notice and answer your blog. Then you can answer them back in Portuguese - and you will find those who speak that language this way.
Hope this is a good idea.
All the best.
that's a great advice. I will start doing that, even tho the content is full english, I could at least bring attention for thoses who doesn't understand very well and try to reach and help them too.