NHS non-clinical work clothes

Hi so next week I start my new job at the NHS. I’ll be working in clinical trials doing mostly admin work and won’t be coming into contact with patients. I don’t have a uniform and have just been told to dress ‘smart casual’. I’m stressing a bit about what to wear? I’m female btw, I’ve got a few pairs of trousers in different colours and some smart white trainers that I wore to my interview. Top wise I do have a couple shirts but they’re really out my comfort zone and I don’t know if they suit me. I was thinking about just getting some plain long sleeve tops in different colours and maybe a cardigan to go with. Would this be suitable? Has anyone else had experience with NHS work clothes or even just an office/admin job and can give me some ideas ty