Hey, Ana.
My intention is to give you encouragement. :)
I am a 23 year old woman, and I traveled to Japan alone from the US (my home country). That was my very first time abroad. Obviously, Japan and European countries are quite different; however, no matter how different they are, they share the same amount of dangerous possibilities. Yes, many people believe Japan is extremely safe, and while that may be true to some extent, there is ALWAYS a possibility for danger to be near. You, especially being a woman, ALWAYS need to be on guard, use your brain, be confident, always have your head up, walk with purpose, and NEVER tell ANYONE that you are alone. EVER.
When I traveled to Japan, my number one goal was to make friends there and that is exactly what I did. I used the Meetup app and met up with people in highly public places. Thankfully, I met wonderful people whom I wholeheartedly look forward to seeing again sometime soon. I loved Japan so much, I am planning to move there within the next five years.
So, my advice to you is to research everything you can about the country you wish to visit. I researched Japan to the point where it no longer seemed foreign to me; in fact, Japan feels more like my home than the US. Also, join Facebook travel groups to gain more advice and wisdom. Knowledge is power!
There are many, MANY women who travel alone and absolutely LOVE it. If I could, I'd travel the entire world all by myself. Traveling alone is a freeing experience and it teaches you a LOT. You would learn so much about yourself and just how capable you are! I never thought I could travel alone, but guess what? I actually did it! Granted, I made many friends, so I tried to keep busy with them. Although, that is the beauty of traveling alone. You are sort of forced into making new friends. ;)
The door of opportunity is wide open!
And of course, hardly anybody knows what is 'eastern europe' as a whole. Serbia is not Poland. One place in Romania is not another place in Romania.
If by 'alone' you mean "withuot other Brazilians" -
you may think of finding local contacts (up to friends and travel companions) beforehand. How do you think: would any of your friends of either sex would like to travel Brazil with a Russian?
If you have any hobbies - local communities of poeple havign the same hobby can be a starting point for making friends even if you are not talkative and communicable:)
I play go (aka baduk aka weiqi - a game) - so possibly in any city in Europe where they have a go club I can go there. Given that this game is far less popular here than in Korea/Japan, the communitiy is rather tight. Also I speak Russian - and there are might be groups of Russian learners.
As to safety...Here it is safe if you travel in the safest way: touristic places, etc.
If you don't like this style, there is of course a numebr of less 'standard' ways to do this which are safe - and a number of those which are dangerous.
