Upgrading Drupal

 Hello All, 

Forgive me, as this is my first forum post and I am still learning about Drupal overall. I've been lurking for a little while and haven't really found a solution for my issue. For starters, I am trying to update my org's drupal website from 9.5.11 to 10.2.5. As a little bit of a breakdown, here is what I have done so far:

Hi,

We are using Drupal as our content management system.  The setup was created 5 years back with the Drupal version 8.8.5 and backend as MySQL PAAS service on Azure.  All the Drupal core files are deployed as docker image in container without composer.  Now we have a mandate to upgrade from Drupal 8.8.5 to latest version 10.2.3 due to End of life of 8.8.5.  We need some guidance on how to do this upgrade and what would be the best approach to do the same?

I updated my site from 10.2.4 to 10.2.5 and then suddenly started getting a message:
 

Error message
Oops, something went wrong.  Check your browser's developer console for more details.

I did and found some additional error messages:

[date & time] [cgi: error] [pid 13498] [client 45.141.215.15:50334] AH02811: script not found or unable to stat: /home/my-site/public_html/cgi-bin

Am I the only one getting this error message?

Regardless, anyone know what I need to do to fix the situation?

I have been using Drupal 7 for 13 years.  Fabulous framework.  Now, as it appears I'm going to have no choice, I am going through the drudgery of figuring out Drupal 10.  Everything that was one step before is now 5 and everything that was a simple function call is now 12 layers deep classes with obscure and convoluted methods.

Never done that before. Here https://www.drupal.org/project/drupal/releases/10.2.4 it says

composer update "drupal/core-*" --with-all-dependencies

but I have access to drupal not server, can I just copy and replace all the files?

I run  $ composer show drupal/core-recommended

I get this: