Medicine clearing is not something you can rely on. It's a rare thing and I believe that for the most part it is open only to people that the unis have previously interviewed and rejected/placed on waitlist.
It sucks that your family is putting this pressure on you to go study something else over some imagined perceptions other people might have, but this is your life and so you should chase your dreams. If this is to pursue Medicine, then take a gap year and apply.
Obviously do work to ace your A-levels, since this is very important. It's been a while since I sat my A-levels but, generally speaking, I remember I was a serial study period waster, so if that's you, best to stop that and use your study periods productively (I know I probably would have done better in my A-levels if I had). Don't be afraid to ask for help in class and maybe try to study with your mates if you can. And practice, practice, practice!
UCAT - you don't want to leave it too late, as this is the single most important factor that will decide what unis you can apply to, and so you want to have some time to ponder over your options after you've sat it. So maybe early September at the latest. Little but consistent practice every day for a month or two before the exam is the trick which has worked for me (three times!), but many people will disagree with me. Loads of threads and guidance online, up to you to decide what approach works best for you. Definitely wouldn't worry about it until the end of year 12 though.
Yes, do get medical work experience if you can, and the earlier you start the better. In-person is best, but online works too these days - Medic Mentor used to run an online programme, they might still do, or there's also the Brighton and Sussex Medical School online programme. Work experience can be volunteering at a hospital or even an old people's homes too.
All of your other plans sound good and reasonable, but don't worry too much about them just yet. Your main priority right now should be acing your A-levels. Good luck!
