Learn is Computer-Based Teaching software that gives basic training in using commands on UNIX and Linux. (Linux is a version of UNIX.) The learn software is free and you can run it on a Windows PC, so you can learn to use a UNIX system before you have access to one.
You will find the instructions for setting up and running the learn software here.
Once you have completed the learn courses, you can hire a cloud server running Linux for as little as $5 per month as described here.
Simon Ritchie gives talks on the history of computing and other subjects.
Ada Lovelace: The Countess who Invented Computer Programming
Alan Turing: Computing Pioneer, War Hero and Gay Icon
Industrial Archaeology Hiding in Plain site
How the British Fell in Love With Tea
Simon's Surrey History Meetup advertises events in Surrey involving history, some online and some in person. For details of all the current events, see here