what do you wear for a wedding?
It depends on whether I'm the bride or the groom.
Seriously, I'd ask the bride & groom, if you know them, or others who are close to the wedding party & knowledgable. Expect you may need to get a suit quickly, so don't waste time, as at least the trousers will need cuffs.
Story: I was a guest of my GF at a mainline Richmond, Virginia society wedding in 1977. The groom had us put up at a downtown hotel, and our first night there he dropped by to greet us, and make sure our arrangements were satisfactory.
While in our room, he asked to see what I would be wearing to the wedding. That kinda surprised me, but I took out a dark business suit from the closet. It was a beautifully custom-tailored designer label, fit me like a glove, the latest fashion, over $1000 which was a good bit of change in 1977.
He sneered at it, and said: "Do you have anything else?" No, I didn't, and why should I?
"Well, OK, I guess you can wear it, you'll be in the back of the church anyway," he said with disdain. I wanted to punch him out. Like people in Richmond would know anything about style? I was furious, but for my GF's sake I accepted the insult.
Moral: the bride & groom expect you to dress to their standard, as you are their guests at their wedding. Find out what most of the other men are wearing and try to comply.