How do I turn off Check engine light
I have a 2014 hyundai I checked the oil it was
Extremely low so I put new oil in an drove it
for about 30 min then my check engine light
came on i don't know why
Get the code read, you could have another issue needing attention. When the problem is resolved the check engine light will turn itself off, usually after one or two cycles. If it stays on then the problem is not resolved. Keep checking your oil level too, it's not typical that your oil level should be "extremely low", that may indicate a problem beyond simple oil consumption.