The car will not start it does turn over but it backfire after 5 to 7 times of trying to start it

Assuming the mechanical timing marks to the camshaft and crankshaft were lined up properly, the timing may be too retarded. Loosen the distributor mounting bolts and rotate the distributor slightly counter-clockwise (CCW). It would help to know year, make, and engine. That's the best I can do, at this point, with the little information provided.