When i was at school i was told i needed a good grounding in Physics to become an Electrician , worst advice i evr got , left school got an apprentiship and spent i day a week at collage (worked the rest) for three years (you can do the course in 6 months if you go constantly but if you have no practical experiance when you become qualified you'll be less than useless to anyone ;) ive been an Electrician for now 20 years and self employed for 14 , best thing i ever did ......... But dont worry too much about school , do the best you can and get the best grades you can , but dont worry too much , try your hardest to get in with a small local electrical company and get an apprentiship with them , they will train you up in the practical stuff and you'll get all the tech stuff from collage.
A small company is always the best , you'll get to do everything from wiring houses to call outs to repairs and breakdowns at big factories , its fantastic training for when you decide to go it alone , then you really start making money :0)
Im in the UK and the hardest part of the training was learning the regulations , the rest is a easy i promise ;)
Im biased but its a fantastic trade to be in , and you'll always be busy