no $x$-intercept; $y$-intercept is at $(0, 3)$ Refer to the graph below.
Work Step by Step
Recall: The graph of a line whose equation is in the form $y=k$ is a horizontal line whose $y$-intercept is $(0, k)$. The line has no $x$-intercept unless the equation of the line is $y=0$. Thus, the $y$-intercept of the graph of $y=3$ is at $(0, 3)$. The graph has no $x-$intercept.