where the weasley live after their house r burnt?

No idea why they chose to do that in the movie. I'm guessing they rebuild, as it's used in the seventh book... Unless they change that.

They can build a new house. They're wizards.

They live at Serius's familys old home.

dont they live for a while at a weasley aunts house (while theyre hiding out)? the one that was at bill and fleur's wedding and talke to harry while he was in his disguise as barry ou who ever he was.

they go live at their aunt's house

idk