We will be coming in on Friday with the party of Zach and Ashley and I want to know if it's okay to bring a small cake in for their wedding?

It's fine

we brought in cakes and decorations for my birthday and it was all good

I doubt that it will be a problem. I brought in separate food for my daughter and there was no issue. To be sure you certainly can call. They are pretty relaxed.

I would call first.