Lots of things matter about the viva and how you succeed at it, but lots of thing really don’t.
It doesn’t matter if you have typos in your thesis, not really. Do your best to proofread and eliminate them, but be prepared to complete corrections after the viva.
It doesn’t matter if you missed a “key” reference from your field. You might have to think about it. You might have to talk about it. But how many more things have you read?
It doesn’t matter if your examiners are experts or not – and it doesn’t matter if you have cited them or not. Whoever your examiners are, they will be professional, they will be prepared and they will be ready to examine you.
It doesn’t matter if your viva is two hours or three hours or longer, except in terms of how tired you feel and whether you need to do something to prepare for that investment of time and energy. Long vivas don’t lead to more corrections.
And it doesn’t matter if you’re nervous. It might not feel comfortable and it could be distracting, but recognising that your viva matters, i.e., being nervous, won’t stop you from succeeding. Work to build your confidence and you’ll see that nervousness is just one more detail of your viva experience.