I've decided not to go university but instead complete a access course in a college situated in London. I currently live in the Lancashire area and will be commuting back and forth 4 times a week (as I will have to fund the course myself, I can't afford to move there)
Is there any form of unlimited train/rail card which I can pay for once and commute back and forth with?
The simplest way to get to London fast from Lancashire is by train from either Warrington Bank Quay, Wigan North Western, Manchester Piccadilly, Stockport, Liverpool Lime Street, Preston and Lancaster which have direct services to London Euston. You can get season tickets between these stations BUT no 16-25 discounts on these I'm afraid.
If you live or if your college is faraway from these stations then imo forget your plan to commute 4 days a week since you're looking at a 2hr journey from Warrington increasing to Lancaster at about 2hr 45 at most with the rest falling inbetween.