Recall the following rule for function transformations:
Vertical shift by c units:

Then, if we begin with the parent function sin(x), the graph of sin(x)-2 corresponds to a vertical shift 2 units down.
Then, to graph f(x)=sin(x)-2, start with the graph of the parent function sin(x) and shift it down by 2 units:
The graph of the parent function is shown as a blue, dotted line.
Therefore, the graph of the function f(x)=sin(x)-2 is: