Hi, I need to show that =[x] is a primitive element of GF(9)=

I have already worked out that the function in the < > is irreducible but I do not know where to go from this.

there are 8 elements in the multiplicative group, what would they be? I guess it would be: 0, 2, x+2, what else? Im very unsure how to do this.

please help me would be appreciated thanks