It would help if you knew the language. Then find some one who knows that language and their version of sign language. Fortunately sign language is a mostly universal concept. You should pick up the difference quickly. It would be better if some one came up with an actual Universal Sign Language, then we could teach everyone, and communication would be less of a problem.
Every country has its own sign language. I am almost deaf and use ASL. I once travelled to Australia and I was not able to read their SL. Sign language cannot be translated. Some signs in our SL are obscene signs in other countries and vice-versa.