Need advice on workflow to implement a new online software as a project

I am looking for a freelancer to provide me with advice on the best way to implement a new online software for my small business. This is a community services agency. The purpose of this software is to provide a link between all departments by increasing efficiency, making operations more cost-effective, and improving data storage and backup.

In particular, the focus of the project is to benefit the Accounting department and other department with reporting. This includes streamlining processes, improving financial accuracy, and developing faster internal operations such as purchase order approval, budgetting etc

I am aiming to have the software implemented within one year; however, I need a freelancer that is able to provide guidance throughout the entire process timeline. This includes preparation, implementation, and maintenance of the program.

If you are experienced in software implementation and have knowledge of project workflow management, I would love to hear from you.

I just need a plan on each steps to implement doing meeting sending emails testing gather feedback etc...

I will need to see something similar that you did to award this technical writting. I will then tell more about the software then