* When do we use *in* instead of *to* ?

For example, a common error I see is: 

> 
> I am going in Miami 
> 
> 
> 

which is wrong and should be

> 
> I am going to Miami 
> 
> 
> 

My understanding is "to" is used when referring to movement and "in" is used when emphasizing events that occurred in a place.

Another confusing example is:

> 
> Go **to** (OR) **in** the sitting room.
> 
> 
> 

Can you clarify which would be correct in this case?