Today we wear a happy smile on our faces还是Today we are weari

有today 这一明确的时间状语,最好用一般现在时,即：
Today we wear a happy smile on our faces.
如果描述状态,也可以用进行时态,但是最好去掉today：
We are wearing a a happy smile on our faces.
你可以参考着两个常用的正确表达：
He often wears a blue jacket.
He is weraing a blue jacket today.