Hi, I`m 30 years old and my greatest dream is to play in a symphonic orchestra. Is it too late for me to start learning how to play an instrument? If not, which instruments are the easiest? I have studied music but my major is singing.

Go ahead and start. It`ll probably be difficult for you to get into a symphony orchestra, but your previous musical experience will make it a lot easier for you to pick things up.
Don`t worry about the age thing. The average life expectancy is around 75-80 years, and if you can`t become a decent musician in 45 years, there`s something wrong.