You ask if "UMAT interviews look at your volunteer/work experience". Answer is no, as there is no such thing as a 'UMAT interview'. UMAT is a test that allows you to enter medical schools/programs/degrees etc.
Medical interviews generally don't directly focus on your volunteer/work experience, however the question may come up..
I would definitely recommend undertaking some work experience in a hospital to get some clinical exposure.
It will show initiative and will enable you to construct answers to other medical related questions in a more clear manner as you'll hopefully gain a relatively basic understanding of the hospital environment and the roles of the doctor and other medical staff.
