Well if you get a job this will probably eat a lot of your hours you might be out recreationally (especially if you work Friday & Saturday evenings). Find cheap hobbies (luckily unis have lots of societies with not much financial commitment).
Other then this be sensible: have a budget, plan a supermarket shop, don’t travel, limit how much you spend on food out the house...
It’s pretty easy to live a basic life at uni as lots of other people do. It’s mostly good organizational skills & avoiding lifestyle choices with costs (such as coffee, lunches on the go, deliveroo orders, buying branded clothes).