Student finance

If I have money to repay some of my loan is that possible instead of waiting until the loan will be written off. For example I have £5000 can I repay that to student finance after I graduate and that be taken off my overall loan of what I need to repay ? And can u do this before I earn the threshold amount for repayments.

Yes you can, but it's not always a good idea. When did you start uni?
If you started between 2012-22 (plan 2), read this:
https://www.moneysavingexpert.com/students/repay-post-2012-student-loan/
If later (plan 5 loan), read this:
https://www.moneysavingexpert.com/students/student-loans-england-plan-5/