Recall that the slope is given by

Since we are not given the y-intercept which is the point when the line crosses the y-axis so we can take the origin as the first coordinate.
Since the slope is positive, we run 1 unit to the right and rise 3 units upward.
Let us draw it on the given grid.
As you can see, we started from the origin (0, 0) and then drawn the point going 1 unit to the right and 3 units upward.
So the other point is (1, 3)
Therefore, the two possible points for a line with slope 3 are (0, 0) and (1, 3)
Please note that you may extend this line and find other points too.