I got a girlfriend in the Dominican Republic she wants to come and visit what do I have to do to get her here

You can sponsor her for a fiancée visa. If you are a US citizen you can sponsor her for a fiancée visa, and she would process at the US consulate in the Dominican republic for her K visa, and once she acquires that, she can travel here but must get married within 90 days after entry. And then after that she could adjust status to get her green card. Alternatively, she could just visit here on a tourist visa, but she cannot adjust status after her visit is done, she must go back home.