Well, your tuition fees will be covered by the Student Loans Company, so the University charges your year fees to the company, which pays them on your behalf. The company charges you the interest that you'll need to repay them when you finish your degree/studies.
I'm not sure what you mean by 'RES' fees, but I presume these are your accommodation fees.
I wouldn't know how this payment is taken, as I went to uni without a student loan for this.
How much do you spend on average each month? Does your bank provide a statement or break it down for you?
A good way to start is:
Open Excel (or Google Sheets)
Write down everything you currently spend money on. EG: Fuel, Phone Bill, Bills (Rent), Entertainment (cinema, trips out etc), Groceries (supermarket shopping), Gifts (presents, friend birthdays), Shopping (clothes), Personal Care (Gym membership), Holidays (trips abroad), etc.
Then if you want to save money, you can reduce the amount spent in these categories.
There are many ways to save money as a student:
https://10ways.com/save/studentsSign up for a student card (UNI Days, Student Beans, NUS Extra) to qualify for discounts on products/days out.
I'll leave you with this motto:
"Anyone who pays full price for anything in life is an idiot. The product or service you seek is discounted somewhere. You just have to find it!"