You can drive the vehicle with a bad serpentine belt.
However if the serpentine belt is cracked or getting stretched then it will eventually either come off the pulleys and shred up or the serpentine belt may completely break and then leave you stranded.
When the serpentine belt breaks or comes off the engine will overheat as the water pump will not be able to operate and your power steering pump will not work as well.
The alternator will also not work as the belt turns the alternator to keep the engine supplied with electricity.
So if your serpentine belt is going bad it's a good idea to replace it.
If you can do the replacement of the serpentine belt yourself it will only cost the price of the serpentine belt which ranges from $15.00 to $50.00 or so depending on the make and model of vehicle.
Some serpentine belts are hard to get too and so a mechanic would be best to do it.
You can get mobile mechanics as well in most places.
A mechanic should charge $50.00 to $150.00 to replace the serpentine belt for labor and the cost of the belt.
A serpentine belt that is bad or going bad may not make any noise at all before it breaks.
However sometimes the serpentine belt may stretch as it starts to break and if it does stretch the serpentine belt can make a squealing or screeching noise.
The noise may get worse as you accelerate.
If you can inspect the serpentine belt and if you notice cracks or the serpentine belt is loose then it needs replaced.
While replacing the serpentine belt it's also a good idea to replace the serpentine belts tension pulley as well as the idler pulley.
Those pulleys can eventually fail and break the belt.
A serpentine belt should last 50,000 to 150,000 miles depending on the quality of the belt.
I replace my serpentine belt every 10 years regardless of mileage because I've had one break and leave me stranded and I had no spare serpentine belt with me.