how can i fix my car?

i have a ford fiesta 1.4 zetec 02 plate it was workin perfectly then i parked on a hill up facing didnt drive for a day then when i went to start it this morning it won't start or turn over at all. thought it might of been the fuel as i was parked on a hill but i have half a tank of fuel so it shouldnt really not start. would be greatful if anyone could help. thanks