Any safety tips for travelling to Brazil or South America?

Hello,
I am thinking about travelling to Brazil next year summer by doing volunteering work with (I to I organisation) or any other travel abroad organisation. But since I don’t know much information about the country, I wanted some useful information. I think I am mostly like to travel on my own and I would explore the country on my own. This would be the first time I am travelling on my own. I might choose to volunteer in a community work, or teach English but I am thinking about doing volunteering work in Rio De Janeiro.
I also wanted some advice if it is safe travelling to the Amazon River and taking a tour there but I am not sure if I will have the time. Plus is there any good place that I should visit.

Thanks

You should have the time of your life but be very weary of areas in South America. The borders of Colombia and Panama are known for being full of Gorillas (merceneries/private armies) who do a lot of kidnapping for ransom. Americans usually stick out from the locals and are targets. Though you're not going to Panama, it happens elsewhere too. Do the tourist thing but take a day and observe the things and way people act. Dress like the locals dress. I recommend no coach purses and designer clothes draped from your body. You wanna look like you belong there, unless you're in a nice area, then dress the way you want. Truthfully, every country has its bad spots. You should do the tourist thing with a friend though. Dont carry a large amount of cash on you or display valuables. I recommend going to the city hall or looking up a vacationers spot and ask questions like what to go see and where not to travel to. It will be a great experience! Good luck.

My general advice is, be very careful, Brazil in general, and Sao Paulo and Rio de Janeiro in particular are very unsafe. Youngsters no only rob you they also kill you at the slightest resistance.
In any case, I ll recommend to get in touch with the Australian Embassy in Brasilia, to get more details about this gigantic country..