Documentation for Multiple Developers Working in the Same Git Project

I have a Git enabled project (say named 'Project A') in which it's always connected to 'main' branch. Knowing the current constraints:

• A project can only have one active branch.
• Each asset can only be assigned to one project.
• Each asset can only have one owner/user.

Is there documentation or a tutorial as a guide for how multiple developers can perform these actions?

• Multiple developers can modify the same existing assets in 'Project A' simultaneously. Is the solution specified here still the only way?
• Proposal to merge:
  • Developer 01 creates a feature branch to edit the existing asset;
  • Developer 01 creates a pull request;
  • Developer 02 reviews the change;
  • Developer 01 merges the feature branch to 'main' branch.

Thanks