Upgrading Drupal

I'm trying to upgrade a simple Drupal 8.9.20 site to Drupal 9 so I can get to 10.  I followed these instructions but when I run composer update I get this.

I'm using the upgrade status module on a Drupal 9.5.3 site, and keep getting a report about invalid permissions. I didn't post this there because I feel it's more of a Drush or Drupal question.

I had the Profile module installed, but ended up removing it when it didn't get used. When I use the Upgrade Status module it reports several of these errors. I have more, but here's an example:

I first banally launched a composer update that miserably failed with some incompatibility.

Problem 1
    - drupal-composer/drupal-scaffold[2.5.0, ..., 2.6.1] require composer-plugin-api ^1.0.0 -> found composer-plugin-api[2.2.0] but it does not match the constraint.
    - Root composer.json requires drupal-composer/drupal-scaffold ^2.5 -> satisfiable by drupal-composer/drupal-scaffold[2.5.0, ..., 2.6.1].

Then I tried to follow the documentation at the URLs below.

Hi- Hoping someone can help!

I'm trying to upgrade a Drupal 8.8.1 site, eventually to D9, but initially to 8.8.4 (which I read somewhere is a needed waypoint for some module). After backing up and manually moving the new core+ files in place, it crashes with the error "'CommerceGuys\Addressing\AddressInterface' not found". Addressing is a library required for the Address module, which is required for Commerce, etc.

According to the Address module info, manual installation isn't possible, so I tried using Composer to reinstall/upgrade Address, but I'm getting this error:

I have a basic page with images and headers, after switching to CKEditor 5 content is empty when I go to edit the page. The content does load when I view the page.  Do I need to do anything to make it work?

Which version are you currently on?

Is there any blueprint or something that you have?