I don't believe gate passes exist in Germany - it's certainly not something I've ever come across outside North America.

You should ask for "meet and assist" (MAAS in airline code) - this is a service that is available to any passenger that needs help with getting to or from their flight, not just unaccompanied minors. MAAS must be booked ahead through the reservation centre.

Edited to add - sorry, didn't take in the bit about being "too proud". Don't know what to suggest then. I don't think you'll be able to go to the gate. And although HAM isn't THAT complicated it is actually possible to go to the wrong place because of the way T1 and T2 are linked airside. It's very easy to turn left instead of right (or vice versa) and come out at the wrong terminal.