I thought you should take G.E.D class

In my opinion is you should take G.E.D classes, even if you know English and you was in high school in your country.
Because G.E.D test is about five subject and The test is limited time. If you take G.E.D classes they gonna teach you, how can you cover your answer in the limited time. In the free G.E.D class has the same kind of practice exam.