how do i remove all data on this MacBook pro

It really depends upon the degree to which you wish to remove the data, from just tossing a few files vs. scrubbing it clean. If you're thinking of selling it, read the document below.

Click on the link to read 'What to do before selling or giving away your Mac.' --> http://support.apple.com/HT201065

"The best way to restore your Mac to factory settings is to erase your hard drive and reinstall macOS." --> How to erase your Intel-based Mac - https://support.apple.com/HT208496

How to erase a Mac with Apple silicon --> https://support.apple.com/HT212030