Most people have to do some. They’re not a punishment. They’re your examiners saying, “Here, you missed this,” or “This is good, but if you try this it will be better.”
Or occasionally, “That’s not how you spell that!”
You can’t predict exactly what you’ll be asked to do. Most PhD candidates will get minor corrections. Some don’t get any. Some are asked to do major corrections or resubmit. Check with your institution’s regulations about what different outcomes could mean for you. Be sure so you can plan ahead.
Expect that you’ll have some corrections to do, but expect that your thesis – and you – will be pretty good by the time your viva comes around.