I have a very basic problem: I want to create a 3D-logo. Therefore I imported a svg from Inkscape an extruded it. I know, that I have to select it in Object Mode, go to Edit Mode and then unwrap it in order to map the imported image on the 3D model. But: there is no Shading/UVs tab. If I create a cylinder or a cube, the Shading/UVs tab is there, if I want to use my extruded object, the tab isn't. What do I have to do to find the Shading/UVs tab? Why is it sometimes hidden and sometimes not??
Curves object's type doesn't have that panel
That panel is available only for Mesh type objects like the cube or the cylinder. Unrwapping is an operation related to faces, polygons, which in the filled and extruded curves are generated "on the fly" and not directly accessible.
Curves are an object type on their own, so you'll need to convert the curve to mesh in order to access those operators.