GARCH Models

[sharon012]

Hi, I am using eviews8.
I am given a task, which says: carry on with the model in equation (1)for the conditional mean return, model the dynamics of the returns' conditional variance.
Equation 1 is Excess return of stock A=alpha+beta*excess return on the S&P500, which is basically a CAPM model.

For doing ARCH, do I do it for the CAPM or the excess return of my stock only?
And also, when I run the GARCH, what variables should I include in the mean equation? Only the excess return of my stock or all the CAPM variables?

The second question is to select the GARCH specification that best characterizes the volatility of my stock. If the best model is GARCH(2,2), how should I interpret this?
I am not certain about the meaning of (2,2).
When I carry on with the GJR and ARCH-M, do I continue with GARCH(2,2) or should I do GARCH(1,1)?

Sorry about so many questions, really don't know how to carry on at the moment.
Thank you for your help!