The UK is well-connected by a public transportation system of buses and trains. For those aged 16-25 (26 for National Express), there are many deals for bus, rail, and the underground (metro). This is handy not only for travel between home and uni but also for day trips and weekend travel across the island.
The UK is a short hop from the rest of Europe and cheap flights can be booked through Ryanair and easyJet. Low-cost flights can be found through other carriers on Skyscanner.