I just bought a Canadian Rangehood (Cypress). The manual that comes
with the it doesn't tell anything on how to connect the wires.

Out of 3 wires for connection, 1 green is for neutral. Then there are
two white wires. One white wire has some letter printed on the
insulation (such as 105C 18AWG etc). The other white wire has nothing
printed on it.

There is no WEB site or technical support number supplied on the
booklet. I am guess the wire with prints is the hot one, and the other
neutral. What the consequence will be if I connect the wire in that
way when it is the other way around?

I opened the junction box inside the rangehood. There were lot of
wirenuts there for the 2 motor, 2 speed rangehood with lights. Each of
those two white wires are connected to black, white, yellow, brown wires
all over.