Hi Sayed,
You have to pass Step 1, Step 2 CK, and Step 2 CS in order to be ECFMG certified so that then you can apply for residency in USA.
These three exams can be taken in any sequence. So for example you can take CS first then you do Step 1 and CK. More on that in this thread
http://www.usmle-forums.com/general-topics-recommended-threads/1223-step-take-first.html
So your question "What happens after CS" may not be a clear question to answer. If you mean what happens after passing all tests and get the ECFMG certificate then here follows the answer;
There's something called the "Match" which is a program administered by the
NRMP in which applicants apply for the various residency programs in all specialties throughout the whole of USA. The application is electronic and is done via
ERAS website. When get to that point you'll gradually understand the details of the application process and we "USMLE Forums" staff and members will help you step by step.
Now, for your other questions;
What constitutes a high score?
Really, this question is redundant and cannot be answered directly. Because it depends on a many factors. Like what is your age, what specialties you are looking for, do you have US clinical experience, ...etc. More on that is available here
http://www.usmle-forums.com/residency-match-recommended-threads/40-matching-filters.html
Generally speaking though, a score of above 90 is considered good and a score of above 95 is considered very good. I was looking at your
public profile and I found that you are a fresh graduate. So this is a very good news and I can tell you that you don't need more than 85 to 90 score to get into Internal Medicine, Psychiatry, Pediatrics, or Family Medicine. Provided you pass all the steps from the first attempt and you do some hands-on clinical rotation here in USA. More about externships here
http://www.usmle-forums.com/tags/externship.html
Will I work and get paid?
Yes, of course. You will be working as a resident and they'll pay you $42,000 to $48,000 in the first year of your residency and your salary will increase annually later.
Why USMLE Step 3?
This is very useful to enhance your CV. Also it's important to get USMLE step 3 if you are looking for H1B Visa. Programs cannot sponsor you if you don't pass USMLE Step 3. More on that is found here
http://www.usmle-forums.com/usmle-step-3-forum/1542-step-3-imgs.html
Another great advantage of doing Step 3 before is detailed in this thread
http://www.usmle-forums.com/usmle-s...24-take-step-3-before-starting-residency.html