Installing Drupal

All the documentation I've found about using the recommended-project template with composer to install Drupal (version 9) lacks detail and explanation.

I want to put my Drupal 9 site in ~/Sites/drupal9.

Exactly how do I do that with recommended-project via composer? Specifically:

What are the advantages and disadvantages of the following ways to install a local Drupal development environment on a Mac (macOS Catalina)?

1. Under MAMP/MAMP Pro (with its built-in apache, mysql, php, phpmyadmin)
2. In Docker
3. With MacPorts installation of apache, mysql, phpmyadmin, php (including composer.phar) already installed

Among criteria would be: ease of additional installation steps; ease of adding modules not in core; ease of updating modules and Drupal itself; and responsiveness of Drupal; and size of installation.

The instructions at https://www.drupal.org/docs/official_docs/en/_local_development_guide.html say to execute the following commands to create a new Drupal application (after ddev has been installed):

# Replace my-site-name!
export SITE_NAME=my-site-name
composer create-project drupal/recommended-project $SITE_NAME
cd $SITE_NAME

And it says that this "will create a new directory and populate it with Drupal (and is dependencies)."

Our hosting is done on Acquia Site Factory. As of now our local dev environment has been on Windows-2016 with Acquia Dev Desktop, on Drupal 8. Our team is growing, had a few folks earlier on but it is going to be 5+ . With those many developers, ADD has problems , I hve experienced slowness, unstable among other things.

What do you recommend we do as a Development env build(local). Preferable on Windows..., I can go to Mac's but not sure about the real advantage....

Our hosting is done on Acquia Site Factory. As of now our local dev environment has been on Windows-2016 with Acquia Dev Desktop, on Drupal 8. Our team is growing, had a few folks earlier on but it is going to be 5+ . With those many developers, ADD has problems , I hve experienced slowness, unstable among other things.

What do you recommend we do as a Development env build(local). Preferable on Windows..., I can go to Mac's but not sure about the real advantage....

Hello, I must be missing something because I'm having an awful hard time installing Drupal 9 on my new site.  I'm using green geeks as a host and have php 7.3, etc.  I don't know what's wrong but I can't get it to work.

Could someone tell me what exactly is supposed to be in my public html folder please?