Seeking Resources to Master Linux Commands for Support Role

I'm preparing to apply for a support role that involves working within Linux environments to verify and troubleshoot backend systems.

I’m looking to deepen my understanding to ensure I’m well-prepared for the responsibilities this role requires.

If anyone could recommend resources, practice environments and specific guides that focus on Linux commands for support and troubleshooting purposes, I’d be truly grateful. I’m particularly interested in material that covers command-line tools commonly used for resource management and backend verification.

Thanks In Advance folks!