There is no specified ceiling for a glider. Above 10000 feet we use oxygen. Usually a portable system fitted into the glider, demand fed or constant supply.
The record altitude until recently was just over 49000 feet. It was raised to about 65000 feet by Steve Fosset and a NASA astronaut using a 2 seater glider and wearing space suits. It was called the Perlan project if you want to do a search for details on the web.
The FAI badge system is for after training to solo standard. It involves cross country flights, height gains from altitude of release and a duration flight of more than 5 hours for the silver badge. They rank in order of:- SILVER, GOLD and then DIAMOND. See
Welcome to the British Gliding Association for more details.
I would recommend you try gliding D-AIHC, try a web search for your nearest site. They will probably do trial lessons. I know there are many excellent clubs in Germany, I flew at a few sites in the late 80's.
More later.