Blender texture paint problem I'm starting with sculpting. So after I sculpted I tried to texture paint my model. But there is weird thing: 

I'm doing this for a first time and I'm very inexperienced. Thanks for answers.
Try looking at your normals in edit mode. Go into edit mode with the object selected, and show the normals (overlays drop-down, shows you the wee blue lines from the centre of each face).
I'm guessing all the faces that won't take your paint stroke are facing the wrong way- inside the mesh.