I need help

i study in what i consider a very bad high school in a very bad envirement(Lycee Garcon),and i need to get the bac in 15 ish,and in 3 months i am gonna be 3eme,seein the envirement i study in and how the high school looks i think i am unable to get that grade in that high school cause of the reason mentioned...although that lycee is the nearest lycee to me,its like 1km from it,idk what to do