Are you in the United States now, or are you still in Nigeria?

You may have to start school all over again if you have a foriegn degree.  US colleges and universities accept transfer credits from foriegn schools on a case by case basis.  Usually foriegn schools have to meet certain critera.  Many do not.

In that case, a community college might be a way to go as they have open acceptance policies (they take everyone), and place students with academic deficiencies in remedial courses to prepare them for college level work.

You will need to take and pass the Test of English as a Foriegn Language (TOEFL).

After that it just depends on where in the US you are, and what programs are available in your local area.  You should inquire at each school to find out what their admission requirements are.

Nursing programs typically require 2 semesters of college level English, one or two pyschology courses (General, and sometimes either Developmental or Abnormal), a sociology course (not all schools require one), 2 semesters of Anatomy and Physiology (which usually must be taken at the same school), and sometimes a Microbiology course.  Some schools may also require a communication arts course and/or computer course.  Many students will take these courses before applying to the nursing program itself, though that is not usually required. 

Because all nursing schools are competitive, it is likely you will be rejected at least once.  Keep trying.

If you are still in Nigeria, you will need to contact the US embassy to inquire as to the requirements for a student visa.  I have no idea what those might be.

Good luck!

 That's been great decision taken by you,become a nurse is not very easy goal you have to strive hard for that but once you have achieved you be able to serve the in right way.LVN nursing is very delightful job to do.