Acquia Multisite structure + migration strategy

Acquia Multisite structure + migration strategy
I can not stress enough the importance of taking the time to build a solid platform architecture to build out a multisite that will be scalable and successful long term. Below are some steps and links to documentation to get started first with the Acquia Cloud Platform and to start thinking about a migration strategy.

Task
Documentation and links
Get access to Acquia Cloud Platform
Setup a local or ide environment
get a second ide	Acquia will follow up
configure your ide	https://docs.acquia.com/ide/start/
pull the prod environment to your cloud ide - this will be empty
use a tool like Acquia BLT
https://docs.acquia.com/blt/install/
Create the code architecture for multi site - Multi Site architecture on Acquia Cloud
Creating a new application on Cloud Platform
https://docs.acquia.com/cloud-platform/create/
Understand what a multisite architecture is
https://docs.acquia.com/cloud-platform/develop/drupal/multisite/
how to setup multisite without blt	
https://support-acquia.force.com/s/article/360042042093-How-to-add-a-new-site-to-a-multisite-on-Acquia-Cloud-Professional-or-Enterprise-without-Acquia-BLT
how to setup multisite with blt	
https://support-acquia.force.com/s/article/360053713173-How-to-Setup-Multisite-on-ACE-with-Acquia-BLT-with-optional-Pipelines-and-Config-Split
Importing an existing application
https://docs.acquia.com/cloud-platform/create/import/
manually or using drush to import your exisiting sites
https://docs.acquia.com/cloud-platform/create/import/archive/drush/
code
use git to move the code repo and theme
https://docs.acquia.com/cloud-platform/create/import/archive/drush/
determine config split management strategy
media
rsync files or upload media files
https://docs.acquia.com/cloud-platform/manage/files/transfer-files/rsync/
migrate api media
https://www.drupal.org/docs/drupal-apis/migrate-api/migrate-destination-plugins-examples/migrating-files-and-images
database / content
Migrate API
https://www.drupal.org/docs/drupal-apis/migrate-api/migrate-api-overview
migrate tools	https://www.drupal.org/project/migrate_tools
migrate examples	https://www.drupal.org/docs/drupal-apis/migrate-api/migrate-destination-plugins-examples
other useful links for SQL to Drupal 8/9	https://medium.com/@colorfield/migrating-sql-in-drupal-8-with-migrate-tools-and-migrate-plus-784dc91897e
https://www.specbee.com/blogs/how-migrate-drupal-8-sql-source-6-simple-steps
or you need to manually rebuild content
Working on Acquia Cloud
Understanding the Acquia Cloud Interface	Cloud Quickstart Workshop
Deployment Best Practices	
Managing Users	
Security and Updates