I believe southern Brazil’s accents and pronunciations are easiest for an American to learn. I learned in Minas Gerais and didn’t understand the difference until I went to Sao Paulo for short visit. While in Sao Paulo it was much easier to pronounce the Portuguese words. The “R’s” are a good example. In Sao Paolo the “R’s” are like an American sounding “R”. In Minas Gerais an “R” sound like “ear-He”.