I am trying to write a simple program that asks the user to enter a number and then I will use that number to decide what the cost of the ticket will be for their given age.
Try the int.TryParse(...) method. It doesn't throw an exception.
int.TryParse(...)
http://msdn.microsoft.com/en-us/library/f02979c7.aspx
Also, you should use && not & in your conditions. && is logical AND and & is bitwise AND.
&&
&