How do I add numbers to my questions?

Are you referring to any questions in your form like radio buttons, Text area etc. those have questions? You can try to use the "Heading" field to add numbers to your questions.

If this is not what you are referring to please provide more details so we can further assist you.

Yes, that is what I mean. But I have a couple of conditionals, so the numbers need to be 'adaptive'. Is that possible?

You can group them using form collapse under survey tool.

Here's how it looks after grouping them using form collapse. You have an option to make it hidden but opened so when conditions is met the form collapse will appear.