Graphics, Figures & Tables ⇒ How can I insert two pictures on the first page?

[Johannes_B]

I still think you don't need and don't want the figures to float, especially since you are now using the H specifier provided by the float-package.

You said the distance is to narrow, i agree with you, but that can easily solved by inserting a \vfill between them.

It is unexpected that the code works very well even after you remove \begin{figure} \end{figure}.

You don't need a figure-environment to insert a graphic. The figure-environment gives the picture and its caption the ability to float to good location inside of your document.
In my example above I used the package capt-of to insert a caption.