The general equation is

where A is the amplitude, the phase shift is C (if it is positive the shift is to the left), D is the vertical shift and the period is given as:

In this case we have the function:

From this we notice that A=3, B=2, C=0 and D=-1; therefore:
Amplitude: 3
Phase shift is zero.
The vertical displacement is -1, this means that the function is translated vertically one unit down.
The period is:

The equation of the midline is:

The graph of the function is shown below:
here the red graph is the sine function, the blue graph is the function g and the green line is the midline.