Pen trouble with Photoshop

I just bought a foldable Lenovo yoga computer and I just uploaded photoshop with it. I tried to use my pen with it but it won't let me paint or do anything it it. I tried a different pen but it won't work. It works on other programs well like zbrush and others. I can draw only on my keypad touchable mouse but for some reason I can't draw with my pen. Can someone please help me.