For a Sera/Angela wedding, I have 2 ideas.
One would be a grand ceremony in Asgard. Thor, King of Asgard, would officiate. Gamora would be Matron of Honor, Balder the Best Man. Angela and Sera would both wear dresses. They feast greatly afterword.
They get space married in casual cloths, officiated by a Space Elvis Impersonator who is actually Loki. They send a video to Thor a week later. Thor cries at the beauty of them.