Google translate tells me casual/unceremonious = "随便" But I always thought "随便" meant "whatever"
I want to say "You can come over whenever, it will be casual"
IMO, the best way to deliver the OP's meaning should be:
There are a lot of other ways to say this, for example:
BTW, I think nowadays younger Chinese people would like to add a
并 like this:
It looks more formal but actually younger people like to use 并 everywhere recently
In Chinese, "随便" has a lot of meanings.
But I think maybe "随便" is not very suitable in your example. "不正式", which means not formal, or "随意", which is used to describe someone or something without many constraints, may be more appropriate. But actually, they don't differ a lot :)