I need to Learn Project Management

I’d recommend capturing all of the requests onto a Kanban board and stating to capture the average cycle time. Then when the next request comes up, it will be a (relatively) simple matter of showing the backlog and asking where this new request fits in with the others based on the average cycle time.

There are a ton of resources to help you learn Kanban with Atlassian having some notable intro blogs. There are a large number of free Kanban apps online too.

Best of luck

On top of my mind I would say

• Turn the Ship Around!: A True Story of Turning Followers into Leaders
• Managing Humans: Biting and Humorous Tales of a Software Engineering Manager
• The Scrum Guide
• The Lean Startup: How Today's Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses