No, such inappropriate content is not typically found in mainstream and legitimate cartoons. They are usually aimed at providing entertainment and positive values for viewers.
The main differences might lie in the visual style and some plot details. The anime could have more dynamic visuals but might tweak a few story elements for better flow.
Suicide girl manga usually has a lot of emotional depth, presenting characters in extreme situations. The art style might be bold and unconventional to make an impact. But be aware that such themes can be disturbing for some readers.
For easy cartoon pencil drawings, you could start by looking at some simple cartoon characters for inspiration. Break the image down into simple shapes in your mind before you start drawing. And don't be afraid to make mistakes; just keep practicing!
For a math cartoon to be funny, it could have funny characters with exaggerated expressions when dealing with math problems. Also, using puns or wordplay related to math can add to the humor.