So the first thing you need to do with your kettlebells is you're going to bring them from the ground up to your shoulders The way i like to do that is coming down, keeping my back nice and flat, picking up my kettlebells and giving it a nice little swing. You're going to power clean it up to your shoulders so now it's resting on your shoulders.
Before you press with your shoulder press you're going to engage your core so you're going to act like someone's going to punch you in the stomach is usually what i tell people. From this position slightly tuck your butt and core and keep them engaged. You're going to drop the elbows slightly and then press overhead.
Bring the kettlebells back down to your shoulders so from a front position it's going to look like this nice and engaged press up. You're trying to get your biceps to almost touch your ears so your arms aren't out in a Y-shape while you're pressing since we don't want you to hurt your shoulders. So just go straight up over your head and back down.