"Vi har et sted å være."

That would probably be "Vi har et sted å bli/bo", but the meaning is almost the same.

I believe the correct translation for the latter would be: 'We have a place to be at', although the 'at' is often omitted in colloquial language.

I think it means more along the lines of "We have somewhere we need to be."

IRT Gary, the 'at' is omitted because it is ungrammatical. In conventional English grammar, a preposition is never used to end a sentence, although this has relaxed considerably in US, Australian and recent usage. It's still ungainly which is why, as you say, it is omitted in speech. As a native English speaker I find this sentence "We have a place to be" almost incomprehensible, it needs an additional verb (we have a place to be living), adverb (a place to be comfortable), or a different verb (a place to live) to make sense. It makes me wonder whether "Vi har et sted å være. " is a Norwegian idiom that doesn't translate well.