Answer
See below.
Work Step by Step
Step 1. To obtain the graph of $f(x)=-3^{x}+1$ from $y=3^{x}$, reflect the curve across the x-axis, then shift 1 unit up. See graph.
Step 2. We can determine the domain is $(-\infty,\infty)$; the range is $(-\infty,1)$; and the horizontal asymptote is $y=1$.