Problems with the 1.8t :( need help

Hello! I need some help in identifying the problem with my car. I have a ’99 1.8t passat. As I turned on the engine the car began to tremble and the engine made more noise than usual. The “check engine” also flashes. I think it’s from the timing belt, but I hope I’m wrong. I just changed it last week at 120.000 km together with the tensioner and the water pump. Do u have any ideas what the problem might be? I was afraid to move the car...more smoke is coming out

White or blue smoke?

Check for any vacuum line leaks, especially by the coolant resivour and the intake manifold.

it was white smoke. I got P0301, misfire cyl1. I was told that it was the ignition coil, but the mechanic swapped the coils, and the problem was still in cyl 1. Now they say that there is a possibility that the valves have carbon (?) but they say that it also can be a valve hit by the piston if the timing belt wasn't tensioned correctly. If the timing belt wasn't correctly tensioned wouldn't i have to have problems in all cylinders? If the valves are carbonized the warranty covers the labour, but if it is the timing belt's fault, i would have to take it to the mechanic that changed it for me, because i have warranty from him for the job done on the timing belt. Who will pay then for the labour already done? :uhoh:

Check the compression on #1. Does the smoke/steam from the exhaust stop when the engine warms up?