Burning smell While driving my vehicle, I noticed a burning plastic smell followed by smoke coming out the vents

Check under hood. may not have been coming from your car.

do not drive it , havee it checked out by a mechanic

Could be an oil leak leaking on the exhaust.

sounds like some wiring may be shorting out behind the dashboard

If it is smoke you will smell it as if there is burning plastic. Some ac units produce really cold air and what you may be seeing is frosted air from the evaporator coming out the vents. It is an indication that the evaporator is actually icing up and not working efficiently.

heater core or one of the hose did you check antifreeze level there could be a leak

Is it smoke or water vapor? If it's smoke, you probably have an electrical problem somewhere. If it's water vapor and you live in a very humid climate, it should dissipate soon after turning on the A/C. Is there a noticeable smell (burning plastic?) along with the smell? If so, have your car checked out by a qualified technician - it could be a fire hazard.

Overheat catalytic converter during your drive??????

something near the a/c vent (under your hood) started to burn or burnt something stuck in there like leaves or plastic etc. check your lines and fuels, make sure nothing's leaking or dried up.

sharp acidic smell would be electrical
sweet smell would be coolant.