There are jobs on campus but they are limited. One option that’s available is that you can apply to be a student ambassador for your subject. This involves attending open days and showing people around the university. This is very competitive though.
There are jobs in the town centre, but they are competitive again, more so since the pandemic. I got a job quite early in first year and worked for all of first and second year, however others in my flat could not get a job.
Past work experience will be beneficial for you, but won’t guarantee anything.