Any one got an idea where to start ? and i want to take train or buses or any suggestion ? Thanks

Ps.I think i'm gonna start from Germany

You can buy an interrail pass that let's you travel ok?

Sounds like a great idea.

spend a few nights in Madrid,, great party town.. some great bars

Avoid London or wear a bullet proof vest.

Starting from Germany for how many days?
You can visit Neuschwanstein Castle in the south of Munich, Berlin . Salzburg( Austria) , is also quite near from Munich and if you travel with companion its quite cheap ( 30 Euros return ticket for up to 5 persons, called the Bayern ticket).
Prague and Budapest are not that far and Amsterdam and Brussels are also quite near from the West. It depends on which countries you want to focus,your budget and how long will be your trip. Enjoy your trip man