I have been made aware of postgraduate research students being targeted by bogus (fake) conference organisers. Early career academics are asked for payment to attend and/or speak at conferences that do not exist. There are blogs and websites that report bogus conferences such as Scholarly Open Access and Bogus Conferences.
Before you commit to attending a conference, discuss it with your supervisor – part of their role is to help you to plan your development. Also, research the conference organiser, look into any badges of authenticity they display on the website and don’t be lured by conferences that are not organised by known, reputable societies or institutions. Other bloggers have provided advice: Journalism Research News, Academia, American Psychological Association