[Unexpected shell and red areas]

@gr5 I used blender to adapt it. @ahoeben mentioned normals and I checked them out in the blender documentation. I didn't know that each face has a direction. The problem was easily fixed by pressing ctrl+N (in blender edit mode) which recalculates the normals.
Thanks for your fast and helpful replies.

[Unexpected shell and red areas]

Hi,

I am new to 3D printing and facing some problems.
I downloaded a model and tried to fix some problem areas causing new problems. I attached the stl file.
1) Please tell me why the bottom of the mouth is red.

2) Please tell me why the bottom the pot is red.

3) The biggest problem is that when I slice it cura thinks that the cup should be closed and adds a face on the top!

The following picture shows the helpers.

I appreciate any help. If I made any major mistakes please tell me so that I can avoid them in the future.

 

thanospotremastered.stl