I would say it depends on if you need the money and if you have the time.
As many have said above you will most likely have the most free time in first year so this would be the best year to see if it’s manageable with your timetable. Maybe wait to see how much free time you end up having with your timetable. But I would preface that the years get more intense as you go on and it may depend on your course. I can honestly say that after second year I would have struggled to keep up with a part time job and my degree as it got far more intense.
If you need a part time job to supplement your studies and really need the money, you could look into things like tutoring where you can manage your own hours or like temp work, the university way have some resources you can you use to look for uni temp work. I would also recommend working over summer if you need extra cash as you won’t have uni work over summer.