Final answer:
Immediately turn off and unplug the computer and ventilate the area, then seek professional help to address the smoke and odor.
Step-by-step explanation:
Upon observing smoke and smelling a strange odor coming from your computer, the most important action to take first is to immediately turn off the computer and unplug it from its power source.
This is critical to prevent any potential fire hazard or further damage to the computer. Afterward, it is advisable to ventilate the area to dissipate any harmful fumes.
Avoid opening the computer case or trying to fix the issue yourself unless you have proper training, as this could cause further damage or personal injury. Instead, seek the assistance of a professional technician to safely address the problem.