My body is extremely stiff and I can't dance at all, how do I change that? ?

my DREAM is to learn Belly Dancing and I'm currently trying to practice with beginners videos on YouTube (I'm too shy to practice with people at the gym, I will do it only when I'm no longer level 0)

And I have found the perfect videos of a really good instructor who explains all moves perfectly but my body is so so stiff and just doesn't move... Plus I have problems doing 2 moves at the same time, I always focus on 1 body part and can't do another move in another body part

So I've been advised to try zumba before belly-dancing.... And although zumba is less complicated than belly dancing, I am still the same 

Way. Too. Stiff. 

I feel discouraged. 

Of course, I do yoga everyday. What else can I do??