Question: what to say to a friend who is getting married?
Answer: "Best wishes!"
"Congratulations!"
"Congratulations on your wedding!"
"We're/I'm so happy for you!"
"Wishing you lots of love and happiness."
"We/I love you. Congrats!"
"Lots of love today and beyond."
"Here's a little something to start your life together." (If you're including a gift.)