Can't connect to MySQL localhost:3306

[Raphael]

@Raphael

We cannot provide support for requests that do not describe in detail the troubleshooting you have already done or that clearly show a lack of will and knowledge to solve the problem.

Please read trough your log and do a minimal google search, you’ve got already hints within your log:

@ClaudioSpcSpa

admin_cgs@servpc:~$ sudo tail -f /var/log/mysql/error.log
2025-03-16 17:06:17 0 [Note] InnoDB: File system buffers for log disabled (block size=512 bytes)
2025-03-16 17:06:17 0 [ERROR] InnoDB: Unable to lock ./ibdata1 error: 11
2025-03-16 17:06:17 0 [Note] InnoDB: Check that you do not already have another mariadbd process using the same InnoDB data or log files.
2025-03-16 17:06:17 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2025-03-16 17:06:17 0 [Note] InnoDB: Starting shutdown…
2025-03-16 17:06:17 0 [ERROR] Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed.
2025-03-16 17:06:17 0 [Note] Plugin ‘FEEDBACK’ is disabled.
2025-03-16 17:06:17 0 [ERROR] Could not open mysql.plugin table: “Unknown storage engine ‘Aria’”. Some plugins may be not loaded
2025-03-16 17:06:17 0 [ERROR] Failed to initialize plugins.
2025-03-16 17:06:17 0 [ERROR] Aborting

So please check running processes, if there is any existing mysql instance running, try the other suggested ways to solve when you google it and so on.