You can either do a BEd with QTS, or a degree followed by a postgraduate teaching qualification that provides qualified teacher status. That can be a PGCE or school centred initial teacher training. Whichever option you do will involve a placement in school.
The best A-levels to do are ones which are core curricular (e.g. English, maths, science subjects, history, geography, a modern language), though there are no specific requirements.