At the moment, most of the documentation is written in English. Some libraries already have initiates to translate documentation into other languages, see Django, for example.
If English is still a barrier for you, I can suggest that in the libraries you are looking for support is:
- search for references in Portuguese: authors of books, forums, communities or even search on twitter
- Open an Issue or report that the library does not support other languages. maybe this is the initial step for them to begin to consider and start something like this
- If some of these libraries already have some translation project, see how you can help the work progress
- As much as possible include, even if self-taught, some time of your week to study a little English. It's super tooling.
Other than that, there is not much to be done, unfortunately.
Maybe some suggestion has been left out, but I hope it already helps.