If I left the stove for 8 hours can I get carbon monoxide poisoning?

Possibly. Carbon monoxide (co) is formed when burning fuel for example gas, but not electric stoves. If the stove is not burning properly or not vented properly then co can build up. If you are concerned there are home co detectors that you can buy at hardware stores, which will tell you if the level is too high.
Typically not. While this is possible, proper ventilation and maintenance should prevent carbon monoxide from forming and building up. A home carbon monoxide detector can help make sure you are not in danger.