Not all cases of immigration law will require the attorney and the client attend any type of a hearing. In the United States most immigrants will need to attend a meeting with an Immigration Officer, but often this is a formality to verify all documented information. An immigration attorney can help prepare you for the meeting and may attend with you if required.
Immigration law is not easy to understand, plus it is constantly changing. Having an immigration attorney greatly increases your chances of successfully completing the immigration process, but it is not a guarantee. The attorney should provide this information after reviewing your case at the consultation stage.