To change the image format to raw, press the menu button, and in the first menu tab, there should be an item called Quality. Select it, and you should see an option for RAW and various JPEG settings. You'll need to "develop" those RAW files using Photos, Aperture, Lightroom, Digital Photo Professional, etc.
Yep, found that many thanks
I have found an online course that potentially could be what I'm looking for, it's not too expensive (£79) to access to course materials for one year and it's specific to Canon cameras which is what I have:
https://moodle.eostrainingacademy.co.uk/course/index.php?categoryid=17
You obviously can't access the modules themselves from that link as you need a subscription but there is a summary of each module there and, if you go back to "Courses" there are several free taster modules.
What do people think? I think I need some direction as I've picked up more from this thread in just a couple of days than in a year of muddling by on my own.