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.

You can remove leading, trailing, and extra spaces between characters and numbers in Excel using TRIM(), SUBSTITUTE() or Find and Replace.

When you type a seven-or-ten-digit phone number into an Excel cell that uses the phone number format, Excel will automatically change the way the number looks so that it appears as a phone number.