You can add a zero before a number in Google Sheets and Excel using this tutorial. You need to change cell formatting or use function.

This feature allows users to add bullet points or other symbols as bullets and add numbers, letters, and roman numeral numbers in front of the text. In Excel, this feature only works with text ...

Repeat the process to add text to another page number in the table of contents by clicking the number, clicking the left arrow, and typing the text.