I did this stuff in Algebra II a few weeks ago, and it confused me for a bit. When adding inside the parentheses, you move to the left. When subtracting in the parentheses, you move right. Both of these only apply to the X axis.
so, (x-1) means you move 1 unit to the right, and (x+2) means you move to the left 2 units.
Now, one thing I can't remember is if the number is OUTSIDE of the parentheses, do you reverse it? Of so, it will look like (x-1) - 3 means you move right 2 and up 3. If its not reversed, you would move down 3.
Also, one more thing: If there is a negative before the parentheses, the parabola goes downwards, not upwards. Feel free to correct anything wrong that I said, as I'm not even sure if I'm right.