How to be reseller of microsoft office?

Hello,

I would begin by becoming a Microsoft Partner:

https://partner.microsoft.com/en-US/partnership

The Microsoft Cloud Partner Program is a global community of partners, offerings, and resources designed to connect your organization with everything it needs to build and deliver successful business solutions. Bolstered by Microsoft's unmatched technology portfolio and extensive customer reach, this unique partner ecosystem will empower your organization with exclusive training, support, service, and sales programs that accelerate innovation and drive growth.

If this is helpful please accept answer.