An Azure DevOps Environment can be created in multiple ways. E.g. through the Azure Portal or through the Azure DevOps Portal. My preferred option is the Azure Portal because you can follow the CI/CD processes, the components, and the structure.
If you do not create the environment through the Azure Portal, it will not be available there either.
Within the Azure portal, an Azure directory, subscription and Resource Group will need to be present/created.
Create an organization and project in the portal through Azure Devops menu. Choose e.g. For a Static Website.
Once the wizard is run, an organization and Project will be created within Azure DevOps. Once they are there, the initial code (e.g. the previously chosen static website) is created.
In the Azure portal you can find the just created organization, the project, and the CI/CD environment.
In the Azure DevOps portal, you can find the code (in Repos) and the CI/CD pipeline.
With Visual Studio code, you can customize the code that has just been placed.
How? You can read that here soon: future link!