Here in Brazil the parents use to make a party for their children, specially in the first year (they make a beautiful themed party, for example, my best friend made a prince party for her baby). Another important age is the 15, if you are a girl you probably will wear a beautiful dress and have a big party with all your family and friends, the boys don't use to give importance for that but they can have a party, too (without dress haha). Me, I don't have my 15 party :/ It is not a cheap thing, you know? 

These are two importants ages but here in Brazil you can have a party every year if you want and have money for it. You need just a cake, something to drink, usually soda or juice, candys (we have the "brigadeiro", is a brazilian candy very delicious and simple to make), pastry and what more you want to serve. The decoration could be simple or more detailed, the usual is to have "congratulation" and your name writed on the wall next the cake or in front of the table like: Parabéns, Ananda!! ou Feliz Aniversário, Ananda!!. And balloons too. 

Another possibility is your friends and family make a surprise party for you, It's more commom between adults. 

Well, is it! Sorry for the long text haha