You’ll be fine
True because vivas go well in the overwhelming majority of cases. Unhelpful because it says nothing of why this happens.
Friends, family, colleagues and supervisors may try to reassure you with the unhelpful truth. And it’s well meant, because they care, they want you to do well and they also believe you will be fine.
To take the kernel of truth – that the viva will go well – and make it helpful, you might have to do a little work.
Ask specific questions about viva expectations. Ask your supervisors to tell you about what examiners actually do. Ask others to support your preparation practically. Remind yourself that you must be talented to have got this far: it can’t simply be luck that has carried you to completion.
You will be fine – for lots of reasons. Find them.