First of all, do a remark for the subject you were 2 marks off. It'll be much quicker than a resit. If you still can't get those 2 marks, then yes, it's a good idea to do resits, provided you think you're capable of teaching yourself while away from college. Usually for courses like Medicine, Vet Science and Dentistry, when the uni accepts resits, they want you to get either AAB or AAA (AAB if they were asking for ABB, AAA if they were asking for AAB). Try not to go through the biomed pathway because it will be annoying for you if you don't like the course, there will be loads of competition from other med applicants doing exactly the same thing, it will be super expensive and you'll be wasting another 3 years.
Use your gap year to give yourself an advantage over other students: get loads of work experience, work on your flaws and make a kick-arse personal statement.