yes you are right

If you have excellent teachers, which can be found even in my nice little Country, and good books, I think 30 days could be plenty of time! The job could be done within 5-7 days, of course you are talking about Venusian days, each one having a duration of approximately 116 terrestrial's days.

Any English speaking country is good for improving your English, but I hope that you will know some basics before you go. You can learn English using Portuguese as your base language here at Italki. Go to: http://www.italki.com/knowledge/learn-English-Portuguese.htm

Any English-speaking country would be great. In Canada, I most places speak both English and French. I would stay away from Quebec, if you want to practice English, because they speak mostly French there. Most other places in the country should be fine!