Yes, believe it or not, Brazil has become one of the premier poker-playing countries in the world, especially for online gamblers. Brazilian authorities don't regulate online gambling in the country. As a result, Brazilian gamblers have the freedom to choose from thousands of online poker rooms.
Yes, you can play online poker in most European countries. Online poker sites like PokerStars, 888poker and PartyPoker are the most popular. However, you should also check the legality of playing poker in the country you're based in before making an account.
