Hi Suraj Garg,
Thanks for using Microsoft products and posting in the community.
I understand that you are having trouble on installing Microsoft AutoUpdate on your MacBook Pro, and I understand how you feel and will do my best to answer your questions.
If you want to force quit the app, you can press the following three buttons at the same time: Option (or Alt), Command, Esc (Escape)1. Alternatively.If you want to know more about the method, you can refer to the follow link.
How to force an app to quit on your Mac - Apple Support
Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology.
What application are you trying to update by downloading and installing Microsoft AutoUpdate? If you want to update office application you can click the following link to download, if you want to download other applications, it is recommended that the best is to download the latest version from the official store.
Update history for Office for Mac - Office release notes | Microsoft Learn
Please feel free to let me know if you have any further updates, thanks.
Best Regards,
Kiki - MSFT | Microsoft Community Support Specialist