The most common reported printer issue is that most users cannot connect canon mg3620 to WiFi.
User should make sure the printer is turned on.
Press and hold wifi button until and unless the ON light flashes.
Press wifi butoon after pressing the color button. check twice on light is lit or not.
Now install the driver and software.
There are more steps need to be taken which is mentioned in this blog : How to connect canon mg3620 to wifi follow all the steps given in this blog carefully.