It’s very easy to feel like that, things like biosecurity you are actually taught in your first weeks of vet school but general it’s a good idea to have an idea of it beforehand. For interviews I would recommend reading the RCVS code of conduct, looking into concepts like one health, animal testing (and the 3Rs) as well as common ethical dilemmas like euthanising a healthy animal!
The vet times is great for staying up to date on current affairs like the dangerous dogs act with XLs (aswell as researching ongoing ones like badger culling etc). You don’t need to have any clue what you want to go into when you graduate, many don’t know for years. It’s easy to get a very unrealistic idea of applicants from the student room as ‘normal’ people don’t like to speak up. Just like it will seem like no one is getting rejected because people are more inclined to share offers rather than rejections x