Radha and Krishna got married in Bhandirvan and Brahma arranged for the marriage and rituals and then he married Radha and Krishna ritually and they became husband and wife. In Garga Samhita, Gargacharya told everyone that he won't be marrying Radha and Krishna together when Gopas asked them to marry the couple. He said Brahma would marry them in Bhandirvan and then Vrishbhanu sent the Shagun to the House of Nanda Rai.
In Brahmavaivarta Purana, it's mentioned that Vrishbhanu and Kalavati decided to marry off 12 years old Radha to brother of Yashoda named Rayana but Radha left the house in distress and Rayana was married to another lady who was Chaya Radha. Brahmavaivarta Purana is a very late and interpolated source, so , either Rayan's story is completely false and interpolated or a devotee of Shri Krishna who was also his aunt was such a great devotee that she was called reflection of real Radha, consort of Krishna when comes to devotion. Garga Samhita doesn't mention Rayana or Ayan, in it Radha and Krishna got married in Bhandirvan but then Akroor took him away and Radha was so shocked and in grief that she collapsed but Krishna promised him that he would return back to her. Then years later Krishna and Ashtabharyas met Radha at Siddhashram and they saw the absolute pure love and devotion of Radha.