Accidentally printed a chocolate mold instead of the object itself
Cura contains a few different so-called &quot;special modes&quot; which changes what the software does with your STL. One such special mode is Mold mode which, instead of recreating the object, creates a mold for the STL. It appears you may have that setting turned on, so disabling it will cause Cura to work as intended.
To answer your other questions:

Most settings affect &quot;rough shape&quot;, properly slicing your STLs to fit your printer and printing material is an essential skill to master in 3D printing. So there is no magic setting to get it all working, you need to tune all your settings according to what you want to print.

Your speed sounds fine, I can't speak for this printer in particular but print jobs taking hours or even days is not out of the ordinary. 3D prints in general take quite some time to complete.

Yes, usually it's called Retraction Length.

Yes it is definitely necessary to set up Cura to your printer settings because Cura needs to know the build volume of your printer and what flavor of firmware is installed on it.