eduroam is a worldwide network, maintained and provided in the UK by an organisation called Jisc, it's not something you'll need to pay for and it's accessible at educational institutions around the world for you to use so long as you attend a university enrolled to use it. If you're staying in halls, you'll likely have Internet access included - as for your mobile Internet usage or private WiFi (if you're living in a shared house), that would be your responsibility to pay for.