We can say either:
get to where
get where
but with an actual place or location, to cannot be dropped:
get to London
get to class
go expresses directional motion (or figuratively, some progress).
get expresses an achieved state (in locative contexts, a destination, a being-at-place).
Where do you want to go?
In which direction, towards which destination, do you want to go?
Where do you want to get?
Where do you want to be? What is your destination or goal?
The two are often interchangeable, but there are times when their nuanced difference might apply. A taxi driver is more likely to ask "Where do you want to go?" because he must take you to your destination and travel the route. If you tell a person you're lost, and don't know where you are, a person helping you out might want to know "Where do you want to get?" That is, tell me where you want to be and I can help you get there.
In my own dialect, these two questions might very well have nearly identical meaning
Where do you wanna get?
Where do you wanna go?
but we can put a special emphasis on the word get
Where do you wanna get?
to mean "Just tell me your destination. I wasn't asking about the route you had in mind."