As a manager you might have already managed many number of projects, we will have a quick walk through on what needs to be done.
1. Understand scope work.
2. Discussion with stakeholders will provide high level plan
3. See your firm repository. Get the standard docs.
4. Consider to brainstorm with team and come up with doc.
5. Identify the project execution methods such as agile, waterfall, ITIL, and others.
6. See project type and come with the plan.