How a graphics designer earns in New York?

Hopefully I am going to New York as an immigrant. I am from Bangladesh. I have ped high school degree. I am doing a job in a foreign farm. I work as a co-ordinator. I am planning to have some preparations before flying to The U.S.A. I have strong attraction in graphics designing filed and I know some photoshop some illustrator, some flash and dream weaver.I am not master in in any as i did not concentrate in that level.I need to know how can I take preparartion to work as a graphics designer? How much a G. dsigner gets there. If i need to take an ociate course my 12 schooling is enough to take admission in any Graphics designing course there? And all other realive answeres are very welcome. How can I take preparation before going there?