Hi @PedroD! 
I think the current maintainers are unfortunately unable to take a more active role, so it would be highly appreciated if others could take over!
You can find all info on how to get started in the Translation Guide.
As far as I can see, the work on the Portuguese translation has not been started yet, so what you could do is
a) Update the Portuguese repo docs to reflect the state of the current Solidity version (pt-portuguese/docs at main 路 solidity-docs/pt-portuguese 路 GitHub vs solidity/docs at develop 路 ethereum/solidity 路 GitHub)
b) Pick a task from the Translation Progress Checklist and start translations 