Most open access journals are legitimate, but there are some that are what this resource calls "predatory," - that is, they are less about open access and the diffusion of knowledge and more about separating you from your money. If you receive an invitaiton to publish in a journal you are not familiar with, talk to your advisor or one of your professors, or your librarian! Also, check the journal against this list to see if it has been identified as a predatory publisher. These publishes will charge you a significant sum to publish an article or [revised] dissertation that does not go through an appropriate peer review process and that can damage your reputation. Note that Jeffrey Beall's work has been subject to criqique!
ORCID--Open Researcher and Contributor ID--provides a persistent digital identifier that distinguishes you from every other researcher and supports automated linkages between you and your professional activities ensuring that your work is recognized. You can sign up for an ORCID for free to get started and see the videos below for more information about building your ORCID profile.