Upgrading Drupal

so I am using Drupal CMS 2.0 on a production server. I recently went to install a module, only for it to screw up my website by throwing out an 403 error forbidden message, even when logging in from a different device. I did get permissions fixed, but now my json lock file is preventing anything from being upgraded. i am modifying the Mercury theme for the site.

I don't have ssh access so everything has to be done through a web interface, whether on Drupal or my web hosting provider site.

I tried upgrading 9.4.5 to 11.3.3 directly by FTP and update.php and got many errors.

I read some where I would need to first upgrade to the latest V9 then to the latest V10 and then to 11.3.3 is that correct?Or is there a faster way?

then....

Since the very old modules trew many errors should I first deactivate all modules, then upgrade Drupal and afterwards update all modules?

Is that the correct way?

I deleted the old files uploaded the new using FTP and changed PHP version of the server to the latest (8.4.)

after that I was trying to use update.php as supposed but I get the following error on the webpage:

The website encountered an unexpected error. Try again later.

After updating the code from 11.2.9 => 11.3.3, I got the error when I want to update the database:

Hello. I’m upgrading a site from Drupal 10 to 11. Post-upgrade, the remote site loads correctly in the browser, but drush sql:* commands fail. For example, drush sql:query "SHOW VARIABLES LIKE 'wait_timeout';"` returns the following:

Error: Call to a member function command() on null in Drush\Commands\sql\SqlCommands->validate() (line 244 of vendor/drush/drush/src/Commands/sql/SqlCommands.php).

Hello everyone!

Yesterday we tried to update our server from Drupal 11.2.8 to 11.3.2 version, using composer and

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

This was not the first time we made this updating till the day we installed this server in 2025, but yesterday we receveid many errors like these: