How do experienced developers approach setting up new project and understand the documentation?

I’m a beginner working on a FastAPI project where I chose MySQL as the database.
I started by reading the FastAPI documentation, but I struggled to understand how to properly set up the project. Then I followed a YouTube tutorial, copied the code, and now I’m more confused than before — I don’t clearly understand what parts of the setup do or how everything fits together. This isn’t a code-specific issue; I’m trying to understand the process of learning and structuring a project.

My question to more experienced developers is:
How do you approach setting up a new backend project (like FastAPI + a database)?

What documentation or resources do you prioritize?

How do you break down and understand concepts from official docs or tutorials?

What is your general workflow when starting a project as a beginner-friendly guideline?

I’m not asking for someone to fix code — I want to learn how to learn and how senior developers understand docs and avoid confusion when setting things up.

Any insight into your process or recommended learning approach would be really helpful.