Tell me about Unix

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Yep, I know nothing about it, but I wanna.

Are there courses that you can recommend for a complete noob? Is there anything I can find out by myself?
My ultimate aim is to be able to handle files and change configs on a Unix server remotely (from a Windows PC).

[X-ray]

Thanks both.

The Unix servers are already up and running at the hospital, and I want to learn about the OS in general and file structure / config also.
I'll find out what version it is and get back to you.

[X-ray]

Thanks all, haven't got details yet of what version we have, but putty would be useful because that's what they are using to edit config files on the server.