There are credentials which an astrologer can get which can assure you of at least their technical competence. Two astrology organizations confer credentials. Tests are given about twice a year at regional and national conferences. All members of NCGR, whether they seek a higher credential or not, sign a code of ethics that defines minimum standards of practice. The initials MAFA tell you only that an astrologer is a dues-paying member of AFA and has signed a code of ethics, not that knowledge or skills have been certified.
Most people have a very satisfying first experience with a professional astrology consultation.
But, as in any field, there are some opportunists, some incompetents, and even a few rip-off artists. As in all matters, let the buyer beware.