Medicine Fourth Choice

My UCAT stats are 2020 UCAT. His GCSE grades are 9- English Language9- Maths 9- Biology 9 - Spanish 9 - French 9- Chemistry 9 - English Literature 9 - Computer Science 8 - Physics 7- Geography Non-contextual and . A*,A* and A*. Have Leicester, Nottingham, Leeds and unsure for the fourth one. Would be very appreciative of some advice. 700 VR, 590 DM and 730 QR

Hi can i ask when should i start doing my volunteering/work experience as GCSE student to get a degree in Medicine