The vertex form of a parabola is \( y = a(x - h)^2 + k \), where \( (h, k) \) is the vertex. The axis of symmetry is the line \( x = h \). Given that the axis is \( x = 0 \), this implies \( h = 0 \). The vertex is a distance of 3 units above the x-axis, so \( k = 3 \). Therefore, the vertex is \( (0, 3) \).