Hi I did biomedical science at uni. At first i worked in a cancer research lab. But now I work in a hospital pathology lab. Lab work is okay but it can be very boring most of the time.
With biology the field is so diverse you can work in immunology, biochemistry, research, microbiology, pathology, zoology, ecology, genetics etc the list is endless.
If you live in the UK generally universities will generally offer specialities e.g zoology. If you decide to do biology you are keeping your options open as normally in the biology department you can mix and match modules and can specialise when doing masters. Or change into speciality after the first year (note this was what happened at my uni) unless you know the field in which you want to study.
I am not sure about major and minor but i think your major is what you have most credits in and minor is the one you have least credits in someone correct me if I am wrong. I hope this helps remember to go for something you are interested in get work experience.