You categorically do not need work experience in a hospital/GP surgery/CT suite/operating theatre or any of the above to apply to medical school.
The simple fact is that a lot of applicants will not have the chance to go to these places. That is OK. Working in a care home or hospice or volunteering in a homeless shelter or working in a charity shop and so on. These are all perfectly valid and valuable pieces of experience. I know people who have been very successful at medical school and they merely worked in a cafe at weekends whilst they completed their A levels. Showing the interviewer(s) you have spent time with people and got out there and made an effort is enough. Maybe you were captain of a team or club, perhaps you did plenty of extramural stuff, D of E, Scouts, military reservist/cadet- it is all useful. I'd argue that care home work is amongst the toughest work environments a person could enter- I've had colleagues tell me that some days they would have to feed, wash and dress 16 residents in a morning: all on their own. That's unlike any hospital ward I've ever experienced. If they can complete that challenge normal ward work must seem a doddle by comparison.
Regarding the UCAT, it is tough and it is just not something you can cram. You should practice and practice and practice, there is no shortcut I am afraid unless you are extremely gifted and particularly good at it without trying.