Does sharpening angle matter?

Pictured: The Angle Cube showing a 15 degree sharpening angle for a kitchen knife on the 1000 grit Naniwa Chocera Pro. 

Yes. The lower the angle, the sharper the edge. BUT a lower angle is more likely to get damaged during use. The edge might chip or fold. The most common thing people will sharpen is their kitchen knives and between 15 and 20 degrees per side is a safe bet for most people. If you’re just starting out, I wouldn’t worry too much about the exact angle, I recommend you focus on maintaining a consistent angle. You want to make sure your wrist isn’t moving during sharpening. Try to moving the knife with bigger muscle groups. You can stand and use your legs, sit and move your core. If your knife edge curves up towards the tip, raise your elbow in order to keep the tip in contact with the stone at the correct angle. And if all that sounds a little too complicated, there are guided sharpeners that let you set the angle.