oil/smoke/fumes shouldnt be getting in the cabin... so you have a hole somewhere

typical for a car with headgasket just done to have residue water/oil in exhaust system which will take 30mins of driving to heat up and clear out

is it coming out the exhaust tip or from engine bay?

could be some oil dripped on to exhaust also, could be a lot of things, you really need to trace where its coming from... or if your reasonably confident its just left over oil etc then run it for 30 mins to see if it clears out