Can someone help me correct these phrases?

Question

Avant que j'ai choisi qu'école a laquelle...

I wanted to say 'Before I chose the school where....'

Answer 1

wow sorry about the many posts! My internet was just crazy

Answer 2

Avant, j’ai choisi l’école où...

Answer 3

Avant de choisir l'école où.....

Sra (aka Mme)

Answer 4

i don't know french that much but i think it should be Avant de choisir l'ecole ou , (like the others write it down)