I live in the state of MO, but work out of the state of KS. What should my primary state be and secondary state be?

If you live in MO (meaning that's where your home is), then you are a MO resident. You work in KS as a non-resident. So you should be filing a non-resifdent state income tax form with KS (you have to pay them taxes on your wages, since you work there), and also a resident tax form with MO.