I need your help with my new site

In principle, I want to modernize my old site
http://www.vom-sonnigen-auenland.de/ and for that, I'm using the IT domain as a test bed.

Main Site: I can not see all menu items. Only when I'm moving the mouse over the menu I'm able to see the items.

Main Site: the big Images should be behind the menu and the logo.

Main Site: the logo should be left from the main menu not above.

All the rest is SUPER.

I hope you can help me

Best Regards, Gerald