university transfer or gap year?

i study bio chem and maths at a-level and i have applied for biomedical science at university and recieved all offers however i do not want to study this course and want to study computer science instead.

im torn between taking a gap year where i can reapply to different universities and have the chance to do online computer science related courses during the gap year and completing work experience.

on the other hand i have no idea whether i can go in to uni for first year and study biomedical science and then either transferring course after a couple weeks or completing first year and then dropping out to reapply or transfer to computer science after a couple.

im so confused on what to do as my parents are also heavly against me taking a gap year although currently seems like the best option for me,

was wondering if theres any routes for me to take to study comp sci eventually or what other have done in similar positions as me. or just any help with the situation would help massively thank you <3