Hi MTAB1380. Welcome to the TestMagic Forums.
You are better off asking the universities you are applying to about their Subject Test requirements, since universities tend to have different policies.
For the General GRE, you should first become familiar with the format of the test. Start working on your vocabulary for the Verbal section, and see how much of Quants you know and how much you need to brush up on.
P.S. In the future, please post Subject GRE questions in the Subject GRE subforum.