What does tu es un putain d'idiot mean?

the direct translation to english is you are a f-ing idiot

Not sure this is related to french.i'm not a relationship master, but it might be that your crush is trying to "flirt" with you and try to get your attention, because he has no other way to show it. or, he just simply might not like you.

1. la rentrée is the first day back to school in the fall.
false (la rentrée is the first day back to school in summer)
la rentrée est le 3 septembre c'est encore l'été, l'automne est le 22 septembre)

2. in france, students take an exam at the end of their high school education. if they pass it, they can go to the university.
true

3. le bac is the test that is taken every year at the end of the year.
false
(en fin de terminale, les lycéens passent le baccalauréat)

4. french teenagers do not generally get part-time jobs because their homework keeps them plenty busy.
false

5 teenagers cannot drive in france until they are 18-years-old.
true
(conduite accompagnée : 15 ans)

6. the homes in france are generally made of different materials than most homes in the united states.
true