There is nothing wrong with 'We have fresh juice [or juices].' But from a marketing/advertising point of view, it is better to say 'Our juice is made from fresh fruit [or fruits].
Do you have different juices, and each juice is made from just one kind of fruit? Or do you have just one juice, and it is made from a combination of several fruits?
In the former case, I would say: 'Our juices are made from fresh fruit.'
In the latter case, I would say: 'Our juice is made from fresh fruits.'