Second Moment of Point on Circumference of Complex Unit Circle

Question

I have a complex random variable $X$ that is drawn uniformly from the circumference of a unit circle. What is $E[X^2]$? I'm unsure how to proceed with this question. $X$ is of the form $a + bi$, thus $X^2 = a^2 -b^2 - 2abi$, and $E[a^2 -b^2 - 2abi] = E[a^2 -b^2]$. From here I'm unsure how to proceed.