I'm going into my first year of A-level in September I'm studying English lit, sociology and criminology and I was wondering if there is and specific stationary or supplies needed I'm planing to obviously get the basics (folders,dividers etc) but is there anything I will 100% need
Have ONE A4 notebook with tear-out pages, and keep a ring-file for notes/papers for each subject at home to file the notes and any other material you have/find for that subject, in topic order if possible so you can find that stuff later. This takes some organisation - you have to diligent about making sure 'all notes get filed' - and making sure they are readable.
So, buy some simple A4 spiral-bound notebooks with tear-out pages - and some 'comfortable' pens.
Buy other stuff just as you feel you need it.