How do you find the sine of the angle between two vectors? I do not know what the sine of the angle between two vectors is. I think it may be the vector created by connecting the tips of the two vectors but I am not sure. 

How do you find the sine of the angle between two vectors?
In general for $\mathbf{a},\mathbf{b}\in\mathbb{R}^3$, we have
$$\|\mathbf{a}\times \mathbf{b}\|=\|\mathbf{a}\|\|\mathbf{b}\|\sin\theta,$$
where $\theta$ is the angle between $\mathbf{a}$ and $\mathbf{b}$.
Translate your two vectors so that their tails are at the origin.  Then draw a line through each of those two vectors.  The smaller of the two angles is the called the "angle between the two vectors".

Hint on how to find it:  The angle $\theta$ between two vectors $\vec u$ and $\vec v$ is given by the formula $$\theta = \arccos\left(\frac {\vec u\cdot\vec v}{|\vec u||\vec v|}\right)$$

Or -- here's a slightly harder way (because it involves calculating a cross product).  You know that $|\vec u\times \vec v| = |\vec u||\vec v|\sin(\theta)$, so find the cross product and all of the norms and then plug in.