Hi 
I’m a total beginner with Unity aswel as Blender and at the moment I’m working on my first ever project.
So I created a little Level (just a couple of empty rooms, but they all cling together so its one big object) in Blender and then tried to import that to Unity.
There my fist problem occured as Unity wouldn’t import my level correctly. Some of my walls just turned into paper and I couldn’t find a solution (I tried the thing with the normals etc).
Now I wanted to apply some texture to my wall so I mapped the model and it worked but than I noticed that the texture wouldn’t line up but just do whatever it wants. It looks pretty funny right now.
Could anyone tell me what I can do to clean up this mess? 
Hello Anni! There are few tutorials that will help you to learn how to fix those problems.
http://cgcookie.com/blender/lessons/creating-an-animated-door-for-unity-3d-part-01/
http://cgcookie.com/blender/lessons/creating-an-animated-door-for-unity-3d-part-02/