Hey there!

For practising in the USA, you will first have to clear the USMLE exam. Once you have successfully got through that, you apply for visa. Your visa might be sponsored, in case of outstanding cases, such as getting exceptionally high scores in USMLE or having being recognized by a notable organization etc. Apart from that, however, it is hard to practise for free in the USA. Once that is done, you go to USA and practise in your chosen field and apply for a residency (if interested). For more information regarding USMLE, you are advised to visit the following links:

https://www.usmle.org/

https://www.usmle.org/bulletin/

Hope this helps. All the best!