<p>I am used to TYPO3 where I just can upload an image within the content element an then just determine the size an so on.</p>

<p>Is there a way to handle images in drupal somehow like this?</p>

I'm just starting to learn about drupal, but here are some of my finds in the Drupal-image-gallery department - perhaps one of these will do what you want:
Flickrup
PROG Gallery
Gallery2