When you come to viva preparation time you will read and re-read your thesis. And you will find typos. That’s to be expected: spellcheck won’t catch everything, and neither will you. It’s not so bad though: make a note of them when you find them and you can correct later.
Instead of going on a typo hunt though, I’d recommend purposefully looking for vague sections of your thesis. Read your thesis carefully, line by line, and see what doesn’t quite make sense. What could be clearer? What might someone struggle with? Spend some time now making notes on that.
Your examiners can probably read past a typo, but they’ll notice something vague and be more likely to dig into it with you in the viva. If you find the vague ahead of time you’ll be more prepared in case it comes up, but you’ll also be better at explaining things in the future.