You may want to review multiplying polynomials first.

Squaring something just means multiplying it by itself. So, to
square a polynomial, just multiply it by itself. For example, to
square 2*x*^{2} + 2*x* + 2, you need to multiply
2*x*^{2} + 2*x* + 2 by 2*x*^{2} +
2*x* + 2, just like you did in the section on multiplying
polynomials. (The answer, in this case, is 4*x*^{4}
+ 8*x*^{3} + 12*x*^{2} + 8*x* +
4.)

Some students are tempted to just square every term and string
them all together somehow. This *does not* work!